BMR and TDEE Calculator UK
Work out your basal metabolic rate and total daily energy expenditure in one step. Enter your details once and both results update instantly, in kg and cm, stone and pounds, or US pounds.
What the two numbers mean
BMR (basal metabolic rate) is the energy your body burns at complete rest just running itself. TDEE (total daily energy expenditure) multiplies BMR by an activity factor to estimate your real daily burn, which is your maintenance calorie level. Eat around your TDEE and weight holds steady; below it and weight falls. To turn TDEE into a target, use the daily calorie needs calculator.
| Activity level | Multiplier | Typically means |
|---|---|---|
| Sedentary | 1.2 | Desk-based, little deliberate exercise |
| Light | 1.375 | Exercise 1 to 3 times a week |
| Moderate | 1.55 | Exercise 3 to 5 times a week |
| Active | 1.725 | Exercise 6 to 7 times a week |
| Very active | 1.9 | Physical job or twice-daily training |
An honest note on accuracy
We use the Harris-Benedict equation, a standard used by UK dietitians. Every BMR formula is still an estimate, accurate to within roughly 10% for most people, and activity multipliers are self-judged. Treat your TDEE as a starting range, watch your real weight trend over several weeks, and recalculate as your weight changes.
If you use a GLP-1 medicine
Treatments like Mounjaro or Wegovy reduce appetite so effectively that many people land far below their needs without trying. Use your TDEE as context to check you are eating enough, keep protein anchored at every meal, and see the nutrition hub, the high-protein guide and safe deficits on treatment. Informational only; not medical advice.
BMR and TDEE questions
What is the difference between BMR and TDEE?
BMR is the energy your body uses at complete rest; TDEE is BMR multiplied by an activity factor, estimating your total daily burn. TDEE is the number to plan maintenance or weight change around.
Which equation does this calculator use?
The Harris-Benedict equation, a standard used by UK dietitians. All BMR equations are estimates, typically within about 10% of measured values for most adults.
How often should I recalculate my TDEE?
Whenever your weight changes meaningfully, roughly every 5 kg or so, or when your activity level changes. A smaller body burns fewer calories, so targets need updating as you lose weight.
Is a higher TDEE better?
Neither better nor worse: it simply reflects your size, age, sex and activity. What matters is how your intake relates to it and that any deficit stays moderate and sustainable.
Where next
Sources: NHS Eatwell Guide • British Dietetic Association food facts. Free tool by Monj (Medstack Ltd, Company No. 16439872) under our editorial and review policy. Educational estimates only; not medical advice; no personal data stored.