Mulch Calculator

How much mulch a bed or tree ring needs in cubic yards and bags, topping up what is already there, with bags and bulk delivery priced side by side.

Mulch

Area shape Rectangle Circle Tree ring Square feet

Length

Use decimals — 10 ft 6 in is 10.5.

Width

Finished depth

ISA and Clemson: 2–3 in for fine mulch like this.

Mulch already there

0 for a new bed. Measure in a few spots.

Bags or bulk

Prices are optional. Enter a bag price and a bulk price to see which costs less for this bed.

Price per bag

Bulk price per cu yd

Delivery fee

Added to the bulk order only.

Bulk minimum

cu yd

Your supplier's delivery minimum, if any.

Mulch to buy

1.85 cu yd

50.0 cu ft · 25 bags of 2 cu ft · 1.42 m³

One cubic yard covers 108 sq ft at 3 in

Bags

2 cu ft each, covering 8 sq ft at 3 in · rounded up

Bulk, by the cubic yard

2 cu yd

1.85 cu yd needed, rounded up to the half yard

3 in is within the 2–3 in that ISA and Clemson give for fine mulch such as shredded wood or bark.

Same bed, other bag sizes

Bag	Bags	Each covers, sq ft	Spare, cu ft
1.5 cu ft	34	6	1.0
2 cu ft	25	8	0.0
3 cu ft	17	12	1.0
0.8 cu ft	63	3.2	0.4

200 sq ft at 3 in. A bag covers its volume spread that deep: the Lowe's listings print 9, 12, 18 and 4.8 sq ft for these four sizes at 2 in.

This bed at other depths

Spread, in	Cu yd	Bags	1 cu yd covers, sq ft
1	0.62	9	324
2	1.23	17	162
3	1.85	25	108
4	2.47	34	81
6	3.70	50	54
9	5.56	75	36
12	7.41	100	27

In 2 cu ft bags. Topping up? Read the row for the inches you spread on top.

How deep, by mulch and spot

Mulch or spot	Depth	Source
Shredded wood or bark	2–3 in	ISA, Clemson
Bark nuggets, arborist wood chips	3–4 in	ISA, Clemson
Under trees and shrubs	3–4 in, out to the drip line, in a ring at least 3 ft in radius	Morton Arboretum, ISA
Perennial beds	A couple of inches	Morton Arboretum
Pine needles	2–3 in	University of Maryland
Shredded leaves, grass clippings	No more than 2 in	Clemson
Compost	About 1 in	University of Maryland
Gravel or stone	1–2 in	University of Maryland, UNL Extension
Rubber mulch in beds	1.5 in	GroundSmart listing
Wet soil, organic mulch	No more than 2 in	ISA
Topping up	Check first; keep the total to 3 in	University of Maryland, ISA
Playgrounds	At least 9 in kept, so 12 in spread; shredded rubber 6 in	CPSC

Keep mulch 3 in off trunks (University of Maryland) and 6–12 in from house walls (Clemson).

How this is calculated

Area: 20 ft × 10 ft = 200 sq ft.

Area: π × (10 ft ÷ 2)² = 78.5 sq ft.

Hole: the 6 in trunk plus 3 in on each side = 12 in, or 1 ft.

Ring: π × ((6 ft ÷ 2)² − (1 ft ÷ 2)²) = 27.5 sq ft, × 1 tree = 27.5 sq ft.

Area: 200 sq ft.

To add: 3 in finished − 0 in already there = 3 in.

To add: nothing, since the 0 in already there reaches the 3 in finished.

Packing down (CPSC, at least 25%): 3 in ÷ 0.75 = 3 in spread.

200 sq ft × 3 in ÷ 12 = 50.0 cu ft; ÷ 27 = 1.85 cu yd.

50.0 cu ft ÷ 2 cu ft a bag = 25.00, rounded up to 25 bags.

50.0 cu ft ÷ 13.5 cu ft a half yard = 3.70, rounded up to 4 half yards: 2 cu yd.

Your supplier's minimum is 0 cu yd, so bulk is billed as 0 cu yd.

25 bags × $0.00 = $0.00.

2 cu yd × $0.00 = $0.00.

Break-even: ($0.00 × 0 cu yd + $0.00) ÷ $0.00 a cubic yard in bags = 0.00 cu yd, about 0.0.

Break-even: $0.00 ÷ ($0.00 − $0.00) a cubic yard = 0.00 cu yd, about 0.0.

A bag covers its volume spread at your depth: 2 cu ft at 3 in is 8 sq ft.

Volumes are not rounded. Bags round up once to whole bags, bulk rounds up to the half yard, and the break-even rounds up to the tenth of a yard.

Depths: ISA, Morton Arboretum, University of Maryland, Clemson and UNL Extension; playgrounds: CPSC. Bag sizes: Lowe's and Home Depot listings; half yards and delivery minimums: Heritage Landscape Supply Group and Estabrook's. Each is listed under the calculator.

Mulch calculator: cubic yards and bags for beds, tree rings and playgrounds

A 20 × 10 ft bed spread 3 inches deep takes 50 cubic feet of mulch: 1.85 cubic yards, or 25 bags of 2 cu ft. The calculator works those figures out for any bed, tree ring or playground, minus the mulch already there, and with a bag price and a bulk price typed in, plus any delivery fee and minimum, it says which costs less for that bed.

How much mulch do you need? Cubic yards, cubic feet and bags

One cubic yard of mulch spread an inch deep covers 324 square feet, according to Clemson Cooperative Extension, so the same yard covers 162 square feet at 2 inches, 108 at 3 inches and 81 at 4. To size a bed by hand, multiply its area in square feet by the depth in inches, then divide by 324 for cubic yards or by 12 for cubic feet:

\text{cubic yards} = \frac{\text{sq ft} \times \text{depth in inches}}{324}

A 20 × 10 ft bed at 3 inches is 200 sq ft × 3 ÷ 12 = 50 cubic feet, and 50 ÷ 27 = 1.85 cubic yards. The mulch calculator puts that volume on its large card, Mulch to buy, because it stays the same whatever bag you pick, and prints the cubic feet, the bag count and the cubic meters under it (1.42 m³, converted with NIST's exact yard).

The order grows in step with the depth: the same 200 sq ft takes 17 two-cubic-foot bags at 2 inches, 25 at 3, 34 at 4 and 50 at 6. Each mulch type in the calculator starts at its own depth: 3 inches for shredded wood or bark and for bark nuggets, 1.5 for rubber in beds, 9 for a wood playground and 6 for a rubber one. A line under the cards then checks the finished depth against arborist and extension guidance: 2 to 3 inches for fine mulch such as shredded wood or bark (the International Society of Arboriculture, ISA, and Clemson), and 3 to 4 for coarse mulch such as arborist wood chips (ISA), with Clemson counting bark nuggets as coarse too.

Bagged mulch is labeled by volume. The Lowe's and Home Depot wood mulch listings this page cites hold 2, 1.5 or 3 cu ft, and the rubber mulch bag 0.8 cu ft. A bag covers its volume spread at your depth: a 2 cu ft bag covers 12 sq ft at 2 inches, the figure on the Sta-Green listing at Lowe's, and 8 sq ft at 3 inches, the figure on the Vigoro listing at Home Depot. The calculator divides the cubic feet by the bag size and rounds up once, so a bed that needs 25.00 bags gets 25 and one that needs 16.67 gets 17.

Loose mulch from a landscape yard is sold by the cubic yard, and both suppliers this page cites, Heritage Landscape Supply Group in the Mid-Atlantic and Estabrook's in southern Maine, also sell a half yard. The Bulk, by the cubic yard card rounds up to the next half yard, so 1.85 cubic yards needed is billed as 2 and 9.26 as 9.5. Type your supplier's delivery minimum and the card shows it whenever it is larger: Heritage applies a 3-yard minimum to every delivery order, and Estabrook's minimums rise with distance, from 2 yards to 5.

The two ways of buying are priced in different units. At 13.5 two-cubic-foot bags to the yard, a $4 bag works out to $54.00 a cubic yard, while bulk adds its delivery fee on top of the yard price. With a bag price and a bulk price typed in Bags or bulk, the page prints which total is lower for this bed and, when bags cost more per yard and a delivery fee or minimum stands in the way, the volume from which bulk would cost less.

How to use the mulch calculator: a front bed priced, then topped up

Take a new 20 × 10 ft bed along a front walk, to be covered in shredded hardwood, and follow it from the first purchase to the next spring's top-up.

1. Leave Mulch on Shredded wood or bark and Area shape on Rectangle, then type 20 for Length and 10 for Width. A side that measures 10 ft 6 in goes in as 10.5, as the hint under Length says.

2. Leave Finished depth at 3 in and Mulch already there at 0. The depth line under the cards reads: "3 in is within the 2–3 in that ISA and Clemson give for fine mulch such as shredded wood or bark."

3. Read the three cards. Mulch to buy shows 1.85 cu yd, with 50.0 cu ft, 25 bags of 2 cu ft and 1.42 m³ beneath it and the note "One cubic yard covers 108 sq ft at 3 in". Bags shows 25, each covering 8 sq ft at 3 in. Bulk, by the cubic yard shows 2 cu yd: the 1.85 needed, rounded up to the half yard.

4. Price both ways. In the Bags or bulk block, type 4 for Price per bag, 40 for Bulk price per cu yd, 75 for Delivery fee and 3 for Bulk minimum. The Bags card adds "About $100.00 at $4.00 a bag". The Bulk card jumps to 3 cu yd, because the supplier's minimum is larger than what the bed needs, and adds "About $195.00: 3 cu yd at $40.00, plus $75.00 delivery".

5. Read the lines under the cards. After the depth line comes the verdict, "Bags are cheaper for this bed by $95.00." Then "At these prices bulk pays off from about 5.4 cu yd." gives the size of job at which delivered bulk would cost less, and the last line prices a bagged yard at $54.00 for 13.5 bags. For this bed you buy 25 bags.

6. The next spring, push a trowel into the bed in a few places before shopping. Say an inch is left. Open the calculator with the price fields at 0, keep the 20 × 10 ft bed and type 1 under Mulch already there. The cards drop to 1.23 cu yd, 17 bags and 1.5 cu yd of bulk, a new line reads "Adding 2 in over the 1 in already there.", and the card note changes to "One cubic yard covers 162 sq ft at 2 in" because only 2 inches are being spread.

Under the cards, Same bed, other bag sizes gives the first spring's count for the other bags on the shelf: 34 bags of 1.5 cu ft, 17 of 3 cu ft or 63 of 0.8 cu ft, each with the cubic feet it leaves over. This bed at other depths lists the bed at 1, 2, 3, 4, 6, 9 and 12 inches. For a top-up, read the row for the inches you spread on top, which in the second spring is the 2-inch row: 1.23 cu yd and 17 bags. The priced bed is saved in this link and the top-up in this one.

Mulch bag sizes: how many make a cubic yard, and what each covers

Bag or unit	Units in a cubic yard	Covers at 2 in	Covers at 3 in
1.5 cu ft bag	18	9 sq ft	6 sq ft
2 cu ft bag	13.5	12 sq ft	8 sq ft
3 cu ft bag	9	18 sq ft	12 sq ft
0.8 cu ft rubber mulch bag	33.75	4.8 sq ft	3.2 sq ft
1 cubic yard of bulk (27 cu ft)	1	162 sq ft	108 sq ft

Mulch calculator examples: big beds, small beds, tree rings and rubber

1,000 sq ft of beds where bulk saves $461.16

Beds around a house that add up to 1,000 sq ft go in with Square feet. At 3 inches they need 250.0 cubic feet, or 9.26 cubic yards. Priced with 1.5 cu ft bags at $4.98, bulk at $39 a cubic yard and a 3 cu yd minimum, the calculator shows:

Bags: 167 (166.67 rounded up, 0.5 cu ft spare), about $831.66
Bulk: 9.5 cu yd (9.26 rounded up to the half yard), about $370.50
Verdict: Bulk is cheaper for this bed by $461.16.
Break-even: about 1.4 cu yd

In 1.5 cu ft bags a cubic yard costs $89.64, 18 bags at $4.98, against $39 for a yard of bulk. With no delivery fee, bags could only win at these prices on a job smaller than the break-even of about 1.4 yards. In 2 cu ft bags the same beds would take 125. Open this estimate.

A 54 sq ft bed where bulk wins by $2.50

This bed is 54 sq ft, priced with 3 cu ft bags at $6 and bulk at $55 a yard loaded into your own truck, so there is no delivery fee and no minimum. It needs 13.5 cubic feet, or 0.50 cubic yards.

Bags: 5 of 3 cu ft (4.50 rounded up, 1.5 cu ft spare), about $30.00
Bulk: 0.5 cu yd, about $27.50
Verdict: Bulk is cheaper for this bed by $2.50.

Per yard the bags are the cheaper product: $54.00 for 9 of them, against $55 for bulk. Bulk still wins because five bags hold 1.5 cubic feet more than the bed needs, while half a yard is 13.5 cubic feet, the bed's volume to the decimal. The break-even sentence is missing here for the same reason: at these per-yard prices it would say bulk never pays off, beside a verdict that says bulk is cheaper. Open the small bed.

Five tree rings 6 ft across

Choose Tree ring and type 6 ft for Ring diameter, 6 in for Trunk diameter and 5 for Trees. The calculator leaves a bare circle 12 in across around each trunk, the 6 in trunk plus 3 in on each side, so each ring covers 27.5 sq ft and the five come to 137.4 sq ft. At 3 inches that is 34.4 cubic feet, 1.27 cubic yards, 18 bags of 2 cu ft (17.18 rounded up) or 1.5 cu yd of bulk. The ring line reads: "Leaves a 12-in circle bare around a 6-in trunk, 3 in off the bark (University of Maryland). ISA: a ring 3 ft in radius is the minimum for most trees."

Six feet across is ISA's minimum ring. The Morton Arboretum extends the mulch to the drip line of the branches on a younger tree, so for a tree whose canopy is wider, measure across the drip line and type that as the ring diameter. Open the five rings.

Rubber mulch in a 200 sq ft bed

Pick Rubber mulch (beds) and the depth becomes 1.5 in and the bag size 0.8 cu ft, the depth and bag on the GroundSmart listing at Lowe's, which rates one 0.8 cu ft bag at 6.4 sq ft at 1.5 inches. The 20 × 10 ft bed takes 25.0 cubic feet, 0.93 cubic yards, or 32 bags (31.25 rounded up, 0.6 cu ft spare), and bulk rounds to 1 cu yd. The depth line reads: "GroundSmart sizes rubber mulch for 1.5 in in beds, against 3 in for wood mulch." For rubber the line states that figure instead of judging your depth against a range. Open rubber at 1.5 in.

A round bed 10 ft across

Choose Circle and keep Diameter at 10 ft. The bed is 78.5 sq ft, and at 3 inches it needs 19.6 cubic feet, 0.73 cubic yards, 10 bags of 2 cu ft (9.82 rounded up, 0.4 cu ft spare) or 1 cu yd of bulk. In 1.5 cu ft bags the same circle takes 14, and in 3 cu ft bags 7. Open the round bed.

Bags or bulk at four sets of prices

Each row is a state of the calculator with prices typed in, read off the cards and the verdict line.

Bed and prices	Bags	Bulk billed	Bags cost	Bulk cost	Cheaper
200 sq ft at 3 in; $4 bags; $40 a cu yd, $75 delivery, 3 cu yd minimum	25 of 2 cu ft	3 cu yd	$100.00	$195.00	Bags, by $95.00
200 sq ft at 3 in; $4 bags; $40 a cu yd, no fee or minimum	25 of 2 cu ft	2 cu yd	$100.00	$80.00	Bulk, by $20.00
1,000 sq ft at 3 in; $4.98 bags; $39 a cu yd, 3 cu yd minimum	167 of 1.5 cu ft	9.5 cu yd	$831.66	$370.50	Bulk, by $461.16
54 sq ft at 3 in; $6 bags; $55 a cu yd	5 of 3 cu ft	0.5 cu yd	$30.00	$27.50	Bulk, by $2.50

The first two rows are the same bed. Taking away the $75 fee and the 3-yard minimum turns a $95.00 win for bags into a $20.00 win for bulk, which is why the delivery fee and the minimum have fields of their own. With the fee in place, the break-even line puts bulk ahead from about 5.4 cu yd; without it, the line says a yard of bulk costs less than a yard in bags with nothing to make up.

How to calculate playground mulch: spread 12 inches to keep 9

The U.S. Consumer Product Safety Commission's Public Playground Safety Handbook says never to use less than 9 inches of loose-fill material under play equipment, except shredded or recycled rubber, for which it recommends 6 inches. It also says loose fill compresses at least 25% over time from use and weather, so a playground that needs 9 inches of wood chips should start with an initial fill of 12. The depth to spread is the depth to keep divided by 0.75:

\text{depth to spread} = \frac{\text{depth to keep}}{0.75}

Pick Playground: wood mulch in the Mulch dropdown and Finished depth fills with 9 in; the page spreads 9 ÷ 0.75 = 12 inches. For a 20 × 10 ft play area that is 200.0 cubic feet, 7.41 cubic yards, 100 bags of 2 cu ft or 7.5 cu yd of bulk, and the depth line says: "Wood fill packs down at least 25% (CPSC), so new fill goes on a third deeper than it has to stay, 12 in to keep 9. The yards above include that." Multiplying the same area by 9 inches gives 5.56 cubic yards and 75 bags, a quarter short once the fill packs down. Open playground wood at 9 in.

Rubber is treated differently on both counts. CPSC recommends 6 inches of shredded or recycled rubber and says it does not compress in the same manner as other loose fill, so the calculator spreads the depth you type. With Playground: rubber mulch the same area takes 100.0 cubic feet, 3.70 cubic yards, 125 bags of 0.8 cu ft or 4 cu yd of bulk, and the line reads: "6 in meets the 6 in CPSC recommends for shredded or recycled rubber, which does not pack down the way wood does." Open playground rubber at 6 in.

For a top-up, the calculator applies the compression to the new fill only, because the old fill has already packed down. Measure what is left in several places, including under the swings and at the end of the slide, where the handbook asks for frequent maintenance, and type the depth you find under Mulch already there. With 5 inches left in an area that has to keep 9, the page adds 4 inches, spreads them 5.33 inches deep to allow for packing, and asks for 3.29 cubic yards, 45 bags of 2 cu ft or 3.5 cu yd of bulk. Open 9 in over 5 in already there.

The handbook's depths are depths after compression, and it warns against CCA-treated wood mulch. Nine inches is its floor for wood fill; the handbook's surfacing table relates depth to the fall height of the equipment, and that table is the one to read before mulching under a tall climber.

Mulch mistakes that waste bags or harm trees

Spreading a full layer over mulch that is still there. University of Maryland Extension warns that mulch can build up to 5, 6 or more inches over time, and says organic mulch should not exceed 3 inches. Measure in a few spots and type the depth under Mulch already there: with 5 in in a bed set to 3, every card reads 0 and the top-up line tells you to rake some out.
Piling mulch against the trunk. The Morton Arboretum calls the mound volcano mulching. University of Maryland Extension says to keep mulch about 3 inches from the base of the trunk, which is the bare circle the Tree ring shape leaves: a 6 in trunk gets a 12 in hole.
Ordering a playground at the depth it has to keep. A plain 9 inches over 200 sq ft is 5.56 cubic yards. CPSC's 25% compression means spreading 12 inches, 7.41 cubic yards, and the playground wood setting adds that for you.
Comparing a bag price with a yard price. A $4 bag and a $40 yard are different units. At 13.5 two-cubic-foot bags to the yard, the bagged yard costs $54.00, and the per-yard line under the cards does that conversion for whichever bag size you pick.
Leaving the delivery fee and minimum out. A bed that needs 1.85 cubic yards, billed at a 3-yard minimum with $40 yards and a $75 fee, costs $195.00 in bulk against $100.00 in $4 bags; with the fee and minimum left at 0, the Bulk card would show $80.00 and the verdict would call bulk cheaper. Ask the supplier for both and type them before you trust the verdict.
Mulching wet ground as deep as dry ground. ISA's 2 to 4 inches is for well-drained sites, and it warns that more than 2 inches of organic mulch can keep wet soils from drying.
Running mulch up to the house. Clemson Cooperative Extension says to keep mulch 6 to 12 inches from building walls so termites cannot use it as a bridge across treated soil; measure the bed from that gap outward.
Mulching shallow-rooted shrubs like a tree. University of Maryland Extension puts no more than 1 inch around shallow-rooted plants such as boxwood, below the 2 to 3 inches the depth line uses for shredded mulch in general.

What to work out before or after the mulch calculator

The calculator has no prices of its own. Mulch prices change by region, and the two supplier pages it cites are local ones: Heritage Landscape Supply Group prices Mid-Atlantic mulch by the yard and the half yard, and Estabrook's shows its delivery fees during online ordering. Type the prices from your own store or landscape yard; with the price fields at 0, the cards show volume only.

Bed volumes carry no settling or waste percentage. ISA and University of Maryland Extension give their depths for the layer as you apply it, ISA's advice is to check the depth of mulch already there before adding more, and the rounding up to whole bags and half yards usually leaves some spare. Mulch that settles or breaks down over the season is what next spring's top-up replaces.

Several separate beds go in as one area: measure each, add their square feet and use Square feet, as the hint under Area says. Inputs are in feet and inches, so a bed measured in meters needs converting first. Weight and tons, pine straw sold in bales, and compost, topsoil or stone are outside this calculator. For stone in a bed, the Gravel Calculator gives cubic yards, tons and bags, and the Area Calculator gives the square feet of triangles, trapezoids and other shapes to type into Square feet.

Mulch calculator FAQ

How many bags of mulch do I need for 200 square feet?

At 3 inches, 200 sq ft needs 50 cubic feet: 25 bags of 2 cu ft, 34 of 1.5 cu ft, 17 of 3 cu ft or 63 of 0.8 cu ft. At 2 inches the 2 cu ft count falls to 17, and at 4 inches it rises to 34.

How many bags of mulch are in a yard?

A cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cu ft, 18 bags of 1.5 cu ft or 9 bags of 3 cu ft. Replacing a full yard with 2 cu ft bags means buying 14.

How much does a yard of mulch cover?

Clemson Cooperative Extension puts one cubic yard at 324 square feet an inch deep. That is 162 sq ft at 2 inches, 108 sq ft at 3 inches and 81 sq ft at 4 inches, and the note on the calculator's large card prints the figure for the inches being spread.

How many yards of mulch cover 1,000 sq ft at 3 inches?

1,000 sq ft at 3 inches is 250 cubic feet, or 9.26 cubic yards, which a supplier selling by the half yard bills as 9.5. In bags it is 125 of 2 cu ft or 167 of 1.5 cu ft. At 2 inches the volume drops to 6.17 cubic yards.

When is bulk mulch cheaper than bags?

Bulk wins once the job is big enough to spread the delivery fee and clear the minimum, and the calculator works that point out from your prices. With $4 bags, $40 a yard, a $75 fee and a 3-yard minimum, a bagged yard costs $54.00 and bulk pays off from about 5.4 cubic yards: the $75 fee divided by the $14 saved on each yard. With no fee or minimum and a bulk yard that costs less than a bagged one, the line says so instead of giving a volume. A very small bed can still go to bags, because bulk comes in half yards. The page rounds the break-even up to the tenth of a yard and hides it when whole-bag and half-yard rounding would make it contradict the verdict.

Can I put new mulch over old mulch?

Yes, as long as the total stays at the depth you want. ISA says to check the depth of mulch already there and break up matted layers with a rake, and University of Maryland Extension says organic mulch should not exceed 3 inches. Type the depth you measured under Mulch already there: with 1 inch left in a 20 × 10 ft bed, the calculator adds 2 inches, 17 bags of 2 cu ft instead of 25.

How much mulch do I need around a tree?

ISA's minimum is a ring 3 ft in radius, 6 ft across, and The Morton Arboretum takes mulch out to the drip line on younger trees. With the Tree ring shape, a 6 ft ring around a 6 in trunk covers 27.5 sq ft once the bare circle at the trunk is left out, and five such rings at 3 inches take 18 bags of 2 cu ft or 1.5 cubic yards of bulk.

How deep should playground mulch be?

CPSC's Public Playground Safety Handbook says never less than 9 inches of loose fill such as wood chips, and recommends 6 inches for shredded or recycled rubber. Wood fill packs down at least 25%, so you spread 12 inches to keep 9.

Is 6 inches of wood mulch enough under a swing set?

CPSC's handbook says no: it sets 9 inches as the least loose fill to use, and the one exception it makes is shredded or recycled rubber, at 6 inches. For wood chips or wood mulch, spread 12 inches so that 9 remain after packing; on a 200 sq ft area that is 7.41 cubic yards. Under the swings and at the end of the slide the handbook asks for frequent maintenance, so measure those spots when you top up.

How much rubber mulch do I need for a flower bed?

GroundSmart's listing sizes its rubber mulch at 1.5 inches in beds, where a 0.8 cu ft bag covers 6.4 sq ft. Picking Rubber mulch (beds) sets that depth and bag size, and a 200 sq ft bed then takes 25.0 cubic feet, or 32 bags.

Should I buy 10% extra mulch for settling?

For beds the calculator adds no percentage, on purpose. The depths ISA, Clemson and University of Maryland Extension give are for the layer as you apply it, and rounding up to whole bags and to the half yard usually leaves some spare: 0.7 cu ft in a 17-bag top-up, 1.5 cu ft in the five 3 cu ft bags of a 54 sq ft bed. Mulch that settles or breaks down during the season is what next year's top-up replaces, and University of Maryland Extension advises replacing it only as needed to keep the original depth. Playground wood is the exception, and there CPSC's 25% compression is built in.

What depth of mulch is best for flower beds?

For shredded wood or bark, 2 to 3 inches (ISA, Clemson). The Morton Arboretum says perennial beds need only a couple of inches; coarse mulch such as arborist wood chips goes 3 to 4 inches (ISA), and Clemson lets pine bark nuggets go as deep as 4. On wet soil, ISA warns that more than 2 inches of organic mulch can keep it from drying. The calculator's depth line checks what you type, and at 5 inches it reads: "5 in is deeper than ISA, Morton Arboretum and Clemson go: they stop at 4 in, and deeper mulch starves roots of air (University of Maryland)."

Which mulch setting do I use for cedar, cypress or dyed mulch?

Use Shredded wood or bark for shredded mulch of any wood or color, and Bark nuggets or wood chips for chunky material. Both start at 3 inches and give the same volume for the same depth; the setting decides which range the depth line checks you against, 2 to 3 inches for shredded and 3 to 4 for nuggets and chips.

How do I order bulk mulch once I know how many yards?

Give the supplier the figure on the Bulk, by the cubic yard card. It is already rounded up to the half yard, or raised to the minimum you typed, so it is a quantity a supplier selling by the half yard can load. Ask for the delivery fee and the minimum before you commit: Estabrook's, for example, shows its fees during online ordering and raises its minimum from 2 to 5 yards with distance. Then type both into the calculator to check that bulk still beats bags for your bed.

Should I buy bags or bulk if the difference is only a few dollars?

Treat a small margin as a tie and decide on the work. In the 54 sq ft example the calculator gives bulk the win by $2.50 on a $30.00 bag order. Bags can be carried to the bed one at a time and leave spare for touch-ups; bulk needs a spot for the pile and a wheelbarrow, and half a yard is the least a half-yard supplier sells. If the break-even sits only a little above your bed's volume, next spring's smaller top-up will fall further below it, which points to bags.

Does the bag count match the coverage printed on the bag?

It should, because both come from the bag's volume. The Vigoro 2 cu ft listing at Home Depot says one bag covers 8 sq ft at 3 inches, and the Bags card prints the same 8 sq ft for a 2 cu ft bag at 3 in. The Lowe's listings print 9, 12, 18 and 4.8 sq ft at 2 inches for 1.5, 2, 3 and 0.8 cu ft bags, which is what the calculator's bag-size table shows at 2 inches. A label that quotes coverage at a different depth has to be compared at that depth.

Why does the calculator round bulk mulch to the half yard?

The two suppliers this page cites sell loose mulch in those steps: Heritage Landscape Supply Group and Estabrook's both list a yard price and a half-yard price. A bed that needs 1.85 cubic yards is billed as 2, and one that needs 9.26 as 9.5, so the bulk cost on the card is for a quantity you can order. If your supplier sells whole yards only, round the bulk card up to the next yard.

Can I save or share a mulch estimate?

Yes. Every value you change from the 20 × 10 ft starting bed goes into the address bar, so sending the link reopens your bed with the same depth, mulch already there, bag size, prices, delivery fee and minimum. The copy button on the Mulch to buy card copies just the cubic yards.

Does the mulch calculator show cubic meters?

Yes, under the cubic yards on the Mulch to buy card: 1.42 m³ for a 20 × 10 ft bed at 3 inches. It converts with NIST's exact yard, so 1 cubic yard is 0.764554857984 cubic meters. The inputs stay in feet and inches.

Sources & References

Content verified by the Smart Calculators Team