Health & Sports
BMI, running pace, fitness, and athletic performance calculators
Health & Fitness Calculators
Take control of your health with our free, science-based health and fitness calculators. Whether you want to check your body mass index, find out how many calories your body burns at rest, or plan your next race pace, our tools give you instant results — no sign-up required.
This category includes three calculators: the BMI Calculator for body weight assessment, the BMR Calculator for daily calorie needs, and the Running Pace Calculator for training and race planning.
BMI Calculator — Know Your Body Mass Index
Body Mass Index (BMI) is a simple, internationally recognized measure that relates your weight to your height. Our BMI calculator gives you an instant result, classifies it according to WHO standards (Underweight, Normal, Overweight, Obese), and shows where you fall on the scale.
Enter your height and weight in either metric (cm, kg) or imperial (ft/in, lb) units and get your BMI in seconds. The calculator also shows the healthy weight range for your height, so you have a clear, actionable reference point. BMI is a useful screening tool — and a great starting point for any health conversation with your doctor.
BMR Calculator — Find Your Daily Calorie Needs
Your Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic functions at complete rest — breathing, circulation, and cell production. Knowing your BMR is the foundation for any nutrition plan, whether your goal is weight loss, muscle gain, or maintenance.
Our BMR calculator uses the Mifflin-St Jeor equation — the most accurate formula recommended by nutrition scientists today. Enter your age, sex, height, and weight, then apply an activity multiplier to get your Total Daily Energy Expenditure (TDEE). The result tells you exactly how many calories you need each day based on your lifestyle.
Running Pace Calculator — Plan Any Race or Training Run
The running pace calculator is your go-to tool for planning any run or race. Enter any two of distance, time, and pace to instantly calculate the third. Toggle between kilometers and miles, choose from standard race distances (5K, 10K, half marathon, marathon), and get detailed split tables for your training.
The calculator also uses the Riegel formula to predict your finish times for other race distances based on your current performance — helping you set realistic goals for your next event.
Your Health & Athletics Toolkit
Together, the BMI, BMR, and Running Pace calculators give you a comprehensive picture of your health and fitness. Use BMI to assess your body composition, BMR to dial in your nutrition, and the pace calculator to structure your training — all in one place, completely free.
We are continuing to build out this category with more health and sports tools. Check back regularly to discover new calculators.
Frequently Asked Questions
BMI (Body Mass Index) is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). In imperial units, the formula is (weight in lb / height in inches²) × 703. Our calculator handles both unit systems automatically.
According to the World Health Organization, a BMI between 18.5 and 24.9 is considered normal or healthy for adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese.
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to sustain vital functions. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor — it represents the total calories you burn in a day including exercise and daily movement. Our BMR calculator computes both.
Our BMR calculator uses the Mifflin-St Jeor equation, which is widely regarded as the most accurate formula for estimating resting metabolic rate in the general adult population. It takes into account your age, sex, height, and weight.
BMI is a useful general screening tool, but it does not account for muscle mass, bone density, age, or sex. Athletes with high muscle mass may have a high BMI without excess body fat. Always discuss your results with a healthcare professional for a complete health assessment.
Yes. Both the BMI and BMR calculators fully support metric (centimeters and kilograms) and imperial (feet, inches, and pounds) units. The default is based on your region, but you can switch at any time.
Choose what you want to calculate (distance, time, or pace), enter the other two values, and the calculator instantly shows you the result along with your speed in both km/h and mph, a complete split table, and race predictions using the Riegel formula.
The Riegel formula (T2 = T1 × (D2/D1)^1.06) predicts your finish time for one race distance based on your performance at another distance. It is widely used by coaches and runners to set realistic race goals.
Yes, all our health and fitness calculators are completely free with no account or sign-up required. Just open the tool, enter your numbers, and get instant results.