UK Calorie Calculator
Work out how many calories you need each day to lose, maintain, or gain weight — from your age, height, weight and activity level.
Last updated: 2026-08-14
Your maintenance calories (to stay the same weight)
2,250 kcal/day
Basal metabolic rate (BMR): 1,452 kcal
To lose weight
1,750
kcal/day (−500)
To maintain
2,250
kcal/day
To gain weight
2,750
kcal/day (+500)
🔒Calculated in your browser. Uses the Mifflin-St Jeor formula — a guide for adults, not medical advice.
How many calories you need depends on your age, sex, height, weight, and how active you are. This calculator uses the Mifflin-St Jeor formula — the one most dietitians and the NHS use — to estimate your basal metabolic rate (what you burn at rest) and your total daily burn. From there it gives you a calorie target for losing, maintaining, or gaining weight.
Frequently asked questions
How many calories do I need a day?
It depends on your age, sex, height, weight and activity. A rough guide: an average adult woman needs about 2,000 kcal a day and an average man about 2,500 kcal to maintain weight — but your own number can be well above or below that. This calculator works out your personal figure.
What is BMR and TDEE?
BMR (basal metabolic rate) is the calories your body burns just to stay alive — breathing, pumping blood, keeping warm. TDEE (total daily energy expenditure) is your BMR multiplied by how active you are, so it includes walking, work and exercise. Your maintenance calories equal your TDEE.
How do I lose weight with a calorie deficit?
Eat fewer calories than your TDEE. A deficit of about 500 kcal a day works out to roughly 0.5 kg (1 lb) of weight loss a week. This calculator's "lose weight" figure already applies that 500 kcal deficit. Don't go below about 1,200 kcal (women) or 1,500 kcal (men) a day without medical advice.
Is the Mifflin-St Jeor formula accurate?
It is the most widely accepted estimate for adults and is accurate to within about 10% for most people. It does not account for muscle mass — very muscular people burn more than it predicts. Treat the result as a starting point and adjust based on what the scale does over a few weeks.