Not medical advice. This tool gives general information, not medical advice. Speak to a doctor or a qualified health professional before changing your diet, sleep or exercise — particularly if you are pregnant, taking medication, or managing a health condition. Full disclaimer.
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Calorie Calculator
Estimate your daily calorie needs using the Mifflin-St Jeor equation. Get your BMR and total daily energy expenditure (TDEE) based on your activity level.
SYSTEM ● ONLINE · LOCAL COMPUTE · ZERO UPLOAD
UNIT // TDEE.CALCLIVE
Maintenance calories (TDEE)
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—
BMR
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TDEE − 500
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TDEE + 500
Quick Answer
How many calories do I need per day?
// Answer
Your daily calorie need is your BMR (basal metabolic rate — calories burned at rest) multiplied by an activity factor, giving your TDEE (total daily energy expenditure). This tool uses the Mifflin-St Jeor equation (1990), which estimates resting energy use from weight, height, age and sex. Over time, eating less than your TDEE tends to lead to weight loss and eating more to weight gain.
Activity multipliers
Level
Multiplier
Sedentary (desk job)
1.2
Light exercise (1-3 days)
1.375
Moderate (3-5 days)
1.55
Active (6-7 days)
1.725
Very active
1.9
These multipliers are a widely used rule of thumb, not measured values. An FAO/WHO/UNU expert report puts a sedentary or lightly active lifestyle at 1.40 to 1.69 times basal metabolic rate, higher than the 1.2 used here, so treat the result as a rough figure.
Why use this tool
A starting point for your goals
Knowing roughly how much energy you use gives you a starting point to compare with what you eat. A daily deficit of about 500 calories is often quoted as roughly 0.5 kg a week, a rule of thumb based on the energy stored in body fat. Studies that tracked real weight loss found this rule overestimates it, because the body uses less energy as weight falls and the change slows over months. These are estimates — individual metabolism varies, so adjust based on real results and consult a professional for personalised advice.
FAQ
Frequently asked questions
BMR is the calories your body burns at complete rest; TDEE is BMR multiplied by your activity level — an estimate of your total daily burn.
The Mifflin-St Jeor equation (Mifflin and colleagues, 1990), built from measurements of 498 healthy adults aged 19 to 78. A 2005 review for the American Dietetic Association found it estimated resting metabolic rate within 10% of the measured value in more people than the other common equations, but it can still be well off for an individual, and older adults and some ethnic groups were under-represented in the studies.
Eating less than your TDEE over time tends to lower weight and eating more tends to raise it. Figures of 500 to 600 calories a day are often quoted; the NHS, for example, suggests around 600. Real change is usually slower than these rules of thumb predict.
No. It provides estimates for general information. Consult a doctor or dietitian for personalised guidance.