Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
BMI Calculator
Body Mass Index (BMI) is the most widely used screening tool for relating a person's weight to their height. It produces a single number that places adults into broad weight categories — underweight, healthy weight, overweight, or obese — and is used by the WHO, the CDC, and the NHS as a first-pass indicator of weight-related health risk. Enter your weight in kilograms and height in centimetres and the calculator returns your BMI in kg/m². The result is meant as a starting point for a conversation with a clinician, not a diagnosis on its own.
BMR / TDEE Calculator
Estimate your daily calorie needs using the revised Harris-Benedict equation, then adjust for activity to get your Total Daily Energy Expenditure (TDEE) — the rough number of calories you burn in 24 hours when you eat a maintenance diet. Enter your weight in kilograms, height in centimetres, age, biological sex, and an activity multiplier (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9). The result is what most nutrition guides call your "maintenance calories" — a starting point for designing a deficit (to lose weight), a surplus (to gain muscle), or a recomposition plan.
Key differences
| BMI Calculator | BMR / TDEE Calculator | |
|---|---|---|
| Category | Health | Health |
| Inputs required | 2 | 5 |
| Result | Your BMI | Daily Calorie Needs (calories) |
| What it does | Body Mass Index (BMI) is the most widely used screening tool for relating a person's weight to their height. It produces a single number that places adults into broad weight categories — underweight, healthy weight, overweight, or obese — and is used by the WHO, the CDC, and the NHS as a first-pass indicator of weight-related health risk. Enter your weight in kilograms and height in centimetres and the calculator returns your BMI in kg/m². The result is meant as a starting point for a conversation with a clinician, not a diagnosis on its own. | Estimate your daily calorie needs using the revised Harris-Benedict equation, then adjust for activity to get your Total Daily Energy Expenditure (TDEE) — the rough number of calories you burn in 24 hours when you eat a maintenance diet. Enter your weight in kilograms, height in centimetres, age, biological sex, and an activity multiplier (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9). The result is what most nutrition guides call your "maintenance calories" — a starting point for designing a deficit (to lose weight), a surplus (to gain muscle), or a recomposition plan. |