Minecraft Enchanting Probability Calculator

Calculate the exact odds of rolling a specific enchantment from a Minecraft enchanting table. Pick your item, material and bookshelf count (0–15), and see the probability of Fortune III, Efficiency V, Sharpness V and every other enchantment per slot — based on the official Java Edition 1.21 algorithm.

Java Edition enchanting odds

Java Edition 1.21

Exact per-slot probability for every enchantment.

Your setup

Item

What you're enchanting. Determines which enchantments can appear.

Material

Material changes enchantability — gold enchants higher, diamond is balanced.

Bookshelves

shelves

0–15. The game caps the bonus at 15 bookshelves, which unlocks level 30.

What you want

Target enchantment

Pick the enchantment you're hoping for, or show all.

Target level

The level you want, or higher.

Results

Chance of Fortune III+

19.4%

best slot (Bottom slot, level 30) · Diamond Pickaxe · 15 bookshelves

Top slot

Level 2–10 (usually 7)

Fortune III+: 0%

Need lvl 7 · costs 1 levels + 1 lapis

Middle slot

Level 6–21 (usually 15)

Fortune III+: 0%

Need lvl 15 · costs 2 levels + 2 lapis

Bottom slot

Level 30

Fortune III+: 19.4%

Need lvl 30 · costs 3 levels + 3 lapis

Is it worth re-rolling?

Expected tries

Expected cost

~15 levels + 15 lapis

Level 30 is the requirement, not the cost — the bottom slot only spends 3 levels and 3 lapis per enchant.

Every enchantment for this slot


Efficiency	IV	80.5%	68.9%
Unbreaking	III	62.7%	62.7%
Fortune	III	32.3%	19.4%
Silk Touch	I	16.1%	16.1%

Efficiency IV

80.5%

Chance at III: 68.9%

Unbreaking III

62.7%

Chance at III: 62.7%

Fortune III

32.3%

Chance at III: 19.4%

Silk Touch I

16.1%

Chance at III: 16.1%

Probability each enchantment appears on the Bottom slot for a Diamond Pickaxe at 15 bookshelves. The first enchantment is weighted by rarity; extra enchantments can cascade on top.

The table can't give you these

Treasure enchantments never come from an enchanting table. Get them from villager trades, fishing, or loot chests instead.

Mending

Curse of Vanishing

villager trades · fishing · loot chests

Your bookshelves set the slot levels. The bottom slot shows the highest level (30 at 15 shelves), but only costs 3 levels and 3 lapis.
Each slot rolls a hidden "enchant power" from its level plus your item's enchantability. Higher power unlocks higher-tier enchantments.
One enchantment is drawn at random, weighted by rarity — common ones (like Efficiency) are far likelier than rare ones (like Silk Touch).
Sometimes a second or third enchantment is added on top, with the chance shrinking each time.

Java Edition 1.21 · updated June 9, 2026

Enchanting mechanics and weights from the Minecraft Wiki (minecraft.wiki). Minecraft © Mojang Studios.

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Minecraft enchanting calculator. Exact per-slot odds of any enchantment from the table.

Pick your item, material and bookshelf count to see the exact percent chance of each enchantment from a Minecraft table, one slot at a time. It runs the real Java Edition 1.21 algorithm, so you can see your true odds of Fortune III before spending a single level or lapis.

What is a Minecraft enchanting calculator?

Enchant a diamond pickaxe with 15 bookshelves and the bottom (level-30) slot offers Fortune III about 19.4% of the time, any Fortune about 32.3%, Efficiency about 80.5%, and Silk Touch about 16.1% — those are the real numbers a Minecraft enchanting calculator hands you, instead of the vague "it's rare" you get from a guide. Feed it your item, its material, and how many bookshelves surround the table, and it works out the chance of every enchantment that can land on each slot.

The enchanting table is deliberately random, so guides usually answer "what are my chances?" with folklore. This calculator answers it with math. It runs the same four-step procedure the game uses: your bookshelf count sets each slot's enchant level, that level plus your item's enchantability rolls a hidden power value, a first enchantment is drawn weighted by rarity, and then extra enchantments can cascade on top. Every probability is computed by exact enumeration of those steps — there is no Monte Carlo guessing — so the percentages match what the game's code actually does.

The headline number it solves for is the one survival players care about mid-game: "is it worth re-rolling for the enchantment I want, or should I trade with a librarian instead?" To answer that, the tool also reports the expected number of re-rolls and the total experience levels and lapis lazuli you would burn through to land your target. For Fortune III on a diamond pickaxe at 15 shelves, that works out to roughly 5 attempts, around 15 levels and 15 lapis on the bottom slot — useful context the moment you decide whether the grind beats curing a zombie villager.

The enchantment list, rarity weights and power windows come from the Minecraft Wiki and are pinned to Java Edition 1.21, including the mace enchantments Density and Breach. Everything runs locally in your browser, so your inputs never leave your device.

How to use this enchanting calculator

The calculator opens on the most-searched setup — a diamond pickaxe at 15 bookshelves, targeting Fortune III — so you see a real answer before touching anything. To check your own situation:

1. Pick your item under "Item" — pickaxe, sword, mace, bow, armor piece, fishing rod, or an enchanted book. This decides which enchantments can appear; a pickaxe can never roll Sharpness from the table, for example.

2. Choose the material. Material changes enchantability, which shifts your odds: gold rolls highest, then iron, then diamond, then stone. Items with no material choice (books, bows, crossbows, tridents, the mace) hide this control because their enchantability is fixed.

3. Set your bookshelves from 0 to 15. This is the biggest lever. The game caps the bonus at 15 shelves, which unlocks the level-30 bottom slot; anything fewer drops your top-tier odds, and at 0 the best enchants are unreachable.

4. Pick the enchantment and level you are hoping for under "What you want," or leave it on "Show all" to see the full ranked table for the bottom slot.

5. Read the result. The big card gives your chance of the target at that level or higher on the best slot. Below it, "Expected tries" and "Expected cost" tell you roughly how many re-rolls, levels and lapis it takes — your answer to "is it worth it?" The per-slot table lists every enchantment's chance so you can compare the top, middle and bottom slots directly.

If your target turns out to be a treasure enchantment (like Mending), the tool flags that it can never come from a table and points you to villager trades, fishing or loot chests instead.

How the enchanting table actually picks an enchantment

The table looks like pure luck, but underneath it is a fixed four-step pipeline. Knowing it is what turns "why do I keep getting Unbreaking?" into a plan.

Step 1 — Bookshelves set the slot levels. When you put an item in, the game rolls a base level from your bookshelf count, then derives the three green numbers you see (top, middle, bottom). The bottom slot is always the highest. At the maximum of 15 bookshelves the bottom slot is always exactly 30 — that is where the "15 bookshelves = level 30" rule comes from. Fewer shelves means lower slot levels, which lock you out of the high-tier enchantments entirely. With 0 bookshelves the bottom slot tops out around level 8, so Fortune III (and most level-30 enchants) is simply impossible — its odds are 0%, no matter how many times you re-roll.

Step 2 — The hidden power roll. Each slot's displayed level is not used directly. The game adds your item's enchantability (a hidden stat that depends on the material) and a small triangular random bonus to produce a "modified enchantment level." Higher enchantability shifts this roll upward, which is why a gold tool (enchantability 22) reaches stronger enchantments more often than a diamond one (enchantability 10), and why a book (enchantability 1) rolls low for its level.

Step 3 — One enchantment is drawn, weighted by rarity. From every enchantment whose power window contains your modified level, the game picks one at random — but not evenly. Each enchantment carries a rarity weight: common ones like Efficiency (weight 10) and Unbreaking (weight 5) are far more likely than rare ones like Fortune (weight 2) or Silk Touch (weight 1). That weighting is exactly why Efficiency shows up roughly five times as often as Fortune on a pickaxe.

Step 4 — Extra enchantments cascade. After the first pick, there is a chance to add a second enchantment, then a third, with the odds shrinking each time. This is why a single bottom-slot roll often gives you Efficiency IV plus Unbreaking III plus Fortune at once — and why "any Fortune" (32.3%) is more likely than Fortune as the only enchantment. The calculator includes these cascade picks in every percentage it shows.

One more rule worth knowing: enchanting a book follows the same steps, but if the roll produces two or more enchantments, the game throws one away at random before you receive the book. That random removal is folded into the book odds, and it is the reason books feel stingier than they look.

Worked examples with real probabilities

Fortune III on a diamond pickaxe at 15 bookshelves — the canonical roll

This is the setup everyone searches. Inputs: diamond pickaxe, 15 bookshelves, bottom slot (level 30). The exact odds: Fortune III appears about 19.4% of the time, any level of Fortune about 32.3%, Efficiency (any level) about 80.5%, Unbreaking (any level) about 62.7%, and Silk Touch about 16.1%. Because Fortune sits at 19.4%, the expected number of re-rolls to see Fortune III at least once is roughly 5 — around 15 experience levels and 15 lapis on the bottom slot, since each bottom-slot enchant costs only 3 levels and 3 lapis. Worth knowing: Fortune and Silk Touch are mutually exclusive, so a roll never offers both at once.

Why 0 bookshelves means 0% for Fortune III

Drop the bookshelf count to 0 and the bottom slot maxes out around level 8 instead of 30. Fortune's power window starts well above what level 8 can reach, so Fortune III's chance is exactly 0% — you could re-roll a thousand times and never see it. This is the single most common reason players complain the table "won't give good enchantments": without enough bookshelves, the high-tier enchants are mathematically off the table, not just unlucky. The fix is bookshelves, not patience.

Gold vs diamond vs stone — does material change the odds?

Material changes enchantability, and enchantability shifts the hidden power roll upward. A gold pickaxe has enchantability 22, diamond 10, stone 5 — so at the same 15 bookshelves, a gold tool reaches Fortune III more often than diamond, which beats stone. The catch is durability: gold tools break almost instantly, so the trick most players use is to enchant a cheap gold pickaxe for the better odds, then transfer the result to a diamond one. Use the material selector above to compare the exact percentages for your case.

Per-slot probabilities for a diamond pickaxe at 15 bookshelves

The bottom slot is almost always the right choice. Here is the bottom-slot breakdown (the screenshot-worthy table), with each enchantment's chance to appear at any level:

Enchantment	Rarity weight	Chance (bottom slot)
Efficiency	10 (common)	~80.5%
Unbreaking	5 (uncommon)	~62.7%
Fortune (any level)	2 (rare)	~32.3%
Fortune III specifically	2 (rare)	~19.4%
Silk Touch	1 (very rare)	~16.1%

The pattern follows the rarity weights exactly: Efficiency (weight 10) appears far more than Fortune (weight 2) or Silk Touch (weight 1). Note these add to more than 100% because a single roll usually grants several enchantments at once through the cascade — getting Efficiency, Unbreaking and Fortune together on one pickaxe is common.

Density and Breach on a mace (Java 1.21)

The mace is the only item that can roll Density and Breach, both added in Java 1.21. At 15 bookshelves on the bottom slot, a mace's only table enchantments are Density, Breach and Unbreaking — Smite, Bane of Arthropods and Fire Aspect are anvil-only on a mace in Java, and Wind Burst is a treasure enchant you can never get from a table. Density and Breach are mutually exclusive, so a roll offers one or the other, never both. This is exactly the 1.21 content that older calculators stuck on version 1.16 cannot show you.

Enchanting-table tips for survival players

Always use the bottom slot. It accesses the strongest enchantments and the cost is almost nothing extra — 3 experience levels and 3 lapis, versus 1 and 1 for the top slot. The level-30 requirement is just a gate to unlock the slot; it does not mean the enchant costs 30 levels.
Build all 15 bookshelves before you start. Place them one block away from the table, on the same horizontal level or one above, and keep that one-block gap truly empty. In Java Edition even a torch, carpet or sign in the gap silently cuts that shelf off — only air (or a replaceable block like a snow layer or short grass) keeps the bonus. Fewer than 15 shelves silently caps your odds, and at 0 the top-tier enchants are impossible, not just rare.
If you want a guaranteed Fortune III, Mending or Silk Touch, trade a librarian instead of re-rolling. The table is random and Mending can never appear there at all, but a librarian villager can be reset (break and replace its lectern) until it offers the exact book you want, then locked in by buying once. For a roughly 1-in-5 enchant like Fortune III, trading is usually faster than the expected 5 re-rolls.
Books accept every non-treasure enchantment, but they roll low. A book has enchantability 1, so its modified power is much lower than a tool at the same slot level — and the game discards one enchantment at random when a book rolls two or more. Use books to harvest enchants you then apply with an anvil, not to fish for a specific high-tier roll.
Enchant a junk item to re-roll. The three offers are tied to a hidden seed that only changes when you actually enchant something. If none of your three options are good, enchant a cheap wooden tool or a book (1 level, 1 lapis) and your real item's offers will refresh.
Gold tools enchant better than diamond, but break instantly. Gold's enchantability of 22 (vs diamond's 10) reaches high-tier enchants more often. A common trick is to enchant a disposable gold tool for the better odds, grab the book or result, then move it onto a diamond tool with an anvil.
Read the expected-cost number before committing. If the calculator says a target needs ~50 re-rolls and hundreds of levels, that is the tool telling you to trade or fish instead. The percentage alone hides how grindy a low chance really is; the expected attempts make it obvious.

Minecraft enchanting calculator — frequently asked questions

What are the odds of getting Fortune III from an enchanting table?

On a diamond pickaxe at 15 bookshelves using the bottom (level-30) slot, Fortune III appears about 19.4% of the time, and any level of Fortune about 32.3%. That means roughly 5 re-rolls on average to see Fortune III once. With fewer bookshelves the odds drop, and at 0 bookshelves Fortune III is impossible.

How many bookshelves do I need for level 30 enchantments?

Exactly 15. The game caps the bonus at 15 bookshelves, which makes the bottom slot show level 30. More than 15 does nothing; fewer than 15 lowers the slot levels and locks you out of the top-tier enchantments.

Why can't I get Mending from the enchanting table?

Mending is a treasure enchantment, and treasure enchantments can never come from a table. Get it from librarian trades, fishing, or loot chests in structures like ancient cities and strongholds instead. The same applies to Frost Walker, Soul Speed, Swift Sneak, Wind Burst, and both curses.

Does a level-30 enchant really cost 30 levels?

No — this is the most common enchanting misconception. Level 30 is the requirement to unlock the bottom slot, but the enchant only costs 3 experience levels and 3 lapis lazuli. You must have at least 30 levels to use the slot, yet you spend just 3 each time. Reaching level 30 in the first place is the real grind — work out exactly how much XP that takes with the Minecraft XP Calculator.

Is the bottom slot always the best one to use?

Almost always, yes. The bottom slot offers the highest-tier enchantments, and it costs only 3 levels and 3 lapis versus 1 each for the top slot — a tiny price for far stronger results. The only reason to use a higher slot is if you specifically want a weaker, single low-level enchant.

Do gold tools enchant better than diamond?

Yes. Gold has enchantability 22 versus diamond's 10, so a gold tool reaches high-tier enchantments more often at the same bookshelf count. The downside is gold's terrible durability — many players enchant a cheap gold tool for the odds, then move the result onto a diamond one with an anvil.

Why do I keep getting Unbreaking and Efficiency instead of Fortune?

Because the first enchantment is drawn by rarity weight, and common enchantments are far likelier. Efficiency has weight 10 and Unbreaking weight 5, while Fortune is only weight 2 and Silk Touch weight 1. So on any roll, Efficiency is about five times as likely to be picked as Fortune — the table is doing exactly what it is designed to do.

Should I re-roll at the table or trade with a librarian?

Use the expected-tries number to decide. If a target enchant has a low chance — say under 20% — you will average several re-rolls and a lot of levels, so resetting a librarian's trades is usually faster and gives a guaranteed result. For common enchants with high odds, re-rolling at the table is fine.

Is this enchanting calculator free?

Yes. There is no account or login, and every calculation runs locally in your browser, so the item, material and bookshelf count you enter never leave your device.

How accurate is it, and which Minecraft version does it use?

It uses the official Java Edition 1.21 enchanting algorithm — the base-level, modified-level, rarity-weight and cascade formulas from the Minecraft Wiki — and computes every probability by exact enumeration rather than simulation. The figures match independent Monte Carlo checks to within a fraction of a percent. Bedrock Edition differs slightly, so treat these as Java odds.

Can I get Fortune III on a book from the table?

It is possible but very unlikely. Books have enchantability 1, so they roll low power for their slot level, and the game discards one enchantment at random when a book rolls two or more. A specific high-tier book enchant like Fortune III is far rarer than on a tool — trading a librarian is the practical route.

What enchantments can a mace get from the table in 1.21?

Only Density, Breach and Unbreaking. Density and Breach are mutually exclusive, so a roll offers one or the other. Smite, Bane of Arthropods and Fire Aspect are anvil-only on a Java mace, and Wind Burst is treasure-only — none of those can come from the table.

Enchanting-table glossary

Bookshelf

A block placed near the enchanting table that raises the available enchant levels. The game counts up to 15 (the cap); 15 shelves make the bottom slot show level 30. Each shelf must be one block away with empty air between it and the table.

Enchantability

A hidden per-material stat that biases the power roll upward. Higher enchantability means better enchantments more often: gold tools 22, iron tools 14, diamond 10, stone 5, books 1, the mace 15. It is why gold enchants higher than diamond.

Modified enchantment level

The hidden power value the game actually uses to pick enchantments. It is the slot's displayed level plus an enchantability roll, multiplied by a small random bonus between 0.85 and 1.15. Each enchantment becomes available only when this value lands in its power window.

Rarity weight

How likely an enchantment is to be drawn when several are eligible. Common = 10 (Efficiency, Sharpness), Uncommon = 5 (Unbreaking, Smite), Rare = 2 (Fortune, Looting), Very Rare = 1 (Silk Touch). A higher weight is picked proportionally more often.

Treasure enchantment

An enchantment that never appears from an enchanting table — Mending, Frost Walker, Soul Speed, Swift Sneak, Wind Burst, Curse of Binding and Curse of Vanishing. You obtain these only from villager trades, fishing, or loot chests.

Cascade

The step where extra enchantments are added on top of the first, with the chance shrinking each time. It is why one bottom-slot roll often grants Efficiency, Unbreaking and Fortune together, and why "any Fortune" is likelier than Fortune alone.

Slot

One of the three enchant offers shown when you insert an item. Top, middle and bottom show increasing levels; the bottom is strongest. They cost 1, 2 and 3 experience levels (and the same in lapis), but the displayed level is only the requirement to use the slot, not the price.

Re-roll

Changing the three offers by enchanting any other item, which advances the hidden enchantment seed. Cheap to do (enchant a junk wooden tool for 1 level and 1 lapis), and the only way to get new options for the item you actually want.

Sources & References

Content verified by the Smart Calculators Team