Is BMI accurate for everyone?

BMI is a quick screening tool, not a diagnosis. It does not distinguish muscle from fat, so very muscular people may read as overweight. It is also less precise across some ethnic groups — use it as a guide alongside other measures.

What is the difference between BMR and TDEE?

BMR is the energy your body burns at complete rest. TDEE adds the calories you burn through daily activity and exercise — it is the number to aim for if you want to maintain your current weight.

How do I lose or gain weight from my TDEE?

Eating roughly 300–500 kcal below your TDEE supports gradual weight loss; eating above it supports weight gain. Sustainable changes beat extreme deficits.

BMI calculator with BMR & calories

BMI, healthy weight range, BMR, and daily calorie needs.

Calculate your Body Mass Index (BMI) and see which WHO category you fall into, the healthy weight range for your height, your Basal Metabolic Rate (BMR), and the daily calories you need to maintain your weight (TDEE).

How the BMI calculator works

BMI is your weight in kilograms divided by your height in metres squared. A BMI under 18.5 is underweight, 18.5–24.9 is normal, 25–29.9 is overweight, and 30 or above is obese.

BMR is estimated with the Mifflin-St Jeor equation, which uses your weight, height, age, and sex. TDEE then multiplies BMR by an activity factor from 1.2 (sedentary) to 1.9 (very active).

The healthy weight range is the weight that would put your BMI between 18.5 and 24.9 at your current height.

Formulas used

BMI = weight(kg) ÷ height(m)²

BMR (male) = 10·kg + 6.25·cm − 5·age + 5

BMR (female) = 10·kg + 6.25·cm − 5·age − 161

TDEE = BMR × activity factor

BMI categories (WHO)

BMI	Category
Below 18.5	Underweight
18.5 – 24.9	Normal weight
25.0 – 29.9	Overweight
30.0 and above	Obese

Frequently asked questions

Is BMI accurate for everyone?: BMI is a quick screening tool, not a diagnosis. It does not distinguish muscle from fat, so very muscular people may read as overweight. It is also less precise across some ethnic groups — use it as a guide alongside other measures.
What is the difference between BMR and TDEE?: BMR is the energy your body burns at complete rest. TDEE adds the calories you burn through daily activity and exercise — it is the number to aim for if you want to maintain your current weight.
How do I lose or gain weight from my TDEE?: Eating roughly 300–500 kcal below your TDEE supports gradual weight loss; eating above it supports weight gain. Sustainable changes beat extreme deficits.