Free Tool

TDEE calculator: work out the calories your body burns in a day

Your maintenance calories, BMR and BMI — plus a daily calorie target for losing or gaining weight, in kg, stone or pounds.

Mifflin-St Jeor equation
kg · st · lb · cm · ft
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Maintenance calories

Press Calculate my calories and your daily figure lands here.

BMR

BMI

Healthy weight

Protein

Where your BMI sits

How it works

1
Fill in your details
Sex, age, weight, height, activity
2
Press calculate
We do the maths for you
3
Get your numbers
Plus a target for every goal

Medical disclaimer

If you have an eating disorder, or a history of one, speak to your GP rather than to a calculator. These figures are general information, not medical advice. The equations behind them are population averages and cannot account for your medical history, medication, pregnancy or body composition. Very low calorie intakes, and weight loss during pregnancy or breastfeeding, should only be undertaken with medical supervision. Decisions about your health belong with your GP or pharmacist.

Where these numbers come from

Built by the CoolDose teamLast updated 27 August 2026

The BMR equation. Mifflin MD, St Jeor ST, et al. “A new predictive equation for resting energy expenditure in healthy individuals.” American Journal of Clinical Nutrition, 1990. PubMed
BMI categories. The NHS bands for underweight, healthy weight, overweight and obese. nhs.uk
Calorie floors. We never show a target below 1,200 calories for women or 1,500 for men. Below that it is hard to hit your protein, vitamin and mineral needs from food, and very low calorie diets are meant to be run under supervision. See NICE guideline NG246 on overweight and obesity management. nice.org.uk
The 7,700 calorie figure. A planning approximation for one kilogram of body weight, not a measured constant. Real loss varies with water, glycogen and muscle. Use it to set a starting target, then adjust to what the scales actually do.

Frequently Asked

Common questions

How the calculator works, and what to do with the numbers it gives you.

Total Daily Energy Expenditure is the number of calories your body burns in a day once your activity is counted. It is your BMR — the energy you would burn lying still — multiplied by an activity factor.

The Mifflin-St Jeor equation, which estimates BMR from your weight, height, age and sex. It is the equation most widely used in UK clinical practice and is generally more accurate than the older Harris-Benedict formula.

It is an estimate. Real energy expenditure varies with body composition, medication, sleep and stress, so treat the number as a starting point and adjust it based on how your weight actually moves over three to four weeks.

The maths is the same, but appetite suppression means many people on Mounjaro or Wegovy eat well below their target without noticing. Use the protein figure as a floor to protect muscle, and follow the plan agreed with your prescriber.

NHS guidance is not to drop below roughly 1,500 kcal a day for men or 1,200 kcal a day for women without medical supervision. Any goal that would fall under that floor is raised to it and flagged.

How the numbers are worked out

BMR comes from the Mifflin-St Jeor equation and is rounded to the nearest calorie.
TDEE is your BMR multiplied by the activity factor shown next to each level.
BMI uses weight in kilograms divided by height in metres squared, on NHS bands.
Weekly goals assume roughly 7,700 kcal per kilogram of body weight.
Loss targets never drop below 1,200 kcal for women or 1,500 kcal for men.

This calculator gives general estimates and is not medical advice. If you are taking a GLP-1 medication such as Mounjaro or Wegovy, follow the plan agreed with your prescriber.

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