Harris-Benedict Calculator

The formula estimates basal metabolic rate (BMR) from sex, weight, height and age. This calculator uses the original 1919 coefficients:

• Men: BMR = 66.5 + 13.75 × weight(kg) + 5.003 × height(cm) − 6.775 × age
• Women: BMR = 655.1 + 9.563 × weight(kg) + 1.85 × height(cm) − 4.676 × age

The result is in kcal/day and represents the energy used at rest. To get your total requirement, BMR is multiplied by a physical activity factor (PAL).

The base value is your basal metabolic rate in kcal/day: the minimum energy for vital functions at rest. The calculator also shows a range that applies activity/stress factors, estimating your daily calorie requirement.

• To maintain weight: eat roughly at your requirement.
• To lose weight: aim for a moderate calorie deficit.
• To gain weight or muscle: plan a calorie surplus.

These are estimates: actual needs vary with body composition and activity.

Knowing your basal metabolic rate is the starting point for planning your diet, managing weight or setting up a training plan — which is why so many people search for a "basal metabolic rate calculator".

Several formulas exist: compare the result with Mifflin-St Jeor and FAO/WHO, or start from the guide to basal metabolic rate formulas.

For a reliable result, enter accurate data:

• Current weight in kg (weigh yourself in the morning).
• Height in cm.
• Age in years and sex.

The formula assumes an average build: in very muscular people or those with high fat mass the estimate is less precise.

Use the estimated requirement as a reference, not a rigid rule.

• Adjust calories towards your goal gradually and track your weight over time.
• For athletic or clinical goals, work with a professional.

When to see a professional: consult a doctor or dietitian before strongly hypocaloric diets, if you have medical conditions, or if you need to lose or gain a lot of weight.

• It is a statistical estimate: actual metabolism can differ by 10-15%.
• It underestimates needs in very muscular people and overestimates them when there is excess fat mass.
• For severe obesity the Mifflin-St Jeor formula is often preferred.