BMI calculator
Your BMI, healthy weight range, calories at rest (BMR) and daily maintenance calories (TDEE) — free, instant, nothing stored.
Estimates from standard population formulas — not medical advice. Talk to a doctor or dietitian before changing your diet, especially if you are pregnant, under 18, or have a medical condition.
Get your daily calorie target, meal plan & AI food scanner
The app turns these numbers into a daily target with a realistic pace, a day of meals from foods you actually eat, and a camera that reads calories off your plate.
Want the goal version — calories and macros for losing, building or maintaining? Calorie & macro calculator →
How this calculator works
What is BMI? Body Mass Index is your weight in kilograms divided by your height in metres squared. Under 18.5 is classed underweight, 18.5–24.9 normal, 25–29.9 overweight and 30+ obese (WHO bands for adults).
What are BMI's limits? It doesn't see muscle, bone density, age or where fat sits, so muscular people can read "overweight" while being lean. Use it as a screening number alongside waist size and how you feel, not as a verdict.
What is BMR? Basal Metabolic Rate — the calories your body burns at complete rest. We use the Mifflin-St Jeor equation: 10 × kg + 6.25 × cm − 5 × age, plus 5 for men or minus 161 for women. It's the most accurate common formula for adults.
What is TDEE? Total Daily Energy Expenditure — BMR multiplied by an activity factor (1.2 sedentary to 1.725 very active). Eat about this much to maintain your weight; the calorie calculator adjusts it for a goal.
Is my data stored? No. Everything is calculated in your browser; nothing you type is sent to us or to any advertiser.