⚖️ BMI & Calorie Calculator

Calculate your Body Mass Index, healthy weight range, basal metabolic rate and daily calorie needs for weight loss, maintenance or gain.

Quick answer: BMI = weight in kg ÷ (height in m)². A healthy adult BMI is 18.5–24.9; for example, 70 kg at 1.75 m gives a BMI of 22.9.

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BMI & Calorie Calculator inputs

years
cm
kg

Result

Your BMI

22.9

Normal weight

Healthy weight for your height: 56.7 – 76.3 kg

BMR (at rest)
1,649 kcal/day
Maintenance (TDEE)
2,267 kcal/day
Lose ~0.5 kg (1 lb) per week1,767 kcal
Lose ~0.25 kg (0.5 lb) per week2,017 kcal
Maintain weight2,267 kcal
Gain ~0.25 kg (0.5 lb) per week2,517 kcal

BMI categories for adults

BMICategory
Below 18.5Underweight
18.5 – 24.9Normal weight
25 – 29.9Overweight
30 – 34.9Obesity class I
35 – 39.9Obesity class II
40 and aboveObesity class III

How daily calories are estimated

Your basal metabolic rate is calculated with the Mifflin–St Jeor equation, widely regarded as the most reliable everyday formula:

Men: 10 × kg + 6.25 × cm − 5 × age + 5
Women: 10 × kg + 6.25 × cm − 5 × age − 161

That figure is multiplied by an activity factor (1.2 for sedentary up to 1.9 for very active) to estimate your total daily energy expenditure. Weight-loss targets never go below 1,200 kcal (women) or 1,500 kcal (men) a day.

This tool is for general information only and is not medical advice. Children, teenagers, pregnant women and people with medical conditions should consult a healthcare professional.

Frequently asked questions

What is a healthy BMI?

For most adults a BMI between 18.5 and 24.9 is classed as a healthy weight, 25–29.9 as overweight and 30 or more as obese. Some health bodies use lower cut-offs for people of South Asian, Chinese and other Asian backgrounds.

How is BMI calculated?

BMI = weight in kilograms ÷ (height in metres)². In imperial units, BMI = 703 × weight in pounds ÷ (height in inches)².

Is BMI accurate?

BMI is a quick screening tool, not a diagnosis. It does not distinguish muscle from fat, so athletes may score as overweight. Waist measurement and a doctor's assessment give a fuller picture.

What are BMR and TDEE?

BMR (basal metabolic rate) is the energy your body uses at complete rest. TDEE (total daily energy expenditure) adds your activity. Eating about 500 kcal below TDEE typically leads to losing roughly 0.5 kg (1 lb) per week.