TDEE Calculator — Total Daily Energy Expenditure

TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day, including all physical activity. It is calculated by multiplying your Basal Metabolic Rate (BMR) by an activity factor. TDEE is your maintenance calories: eating exactly this number keeps your weight stable. Eating below it causes weight loss; above it causes weight gain.

TDEE = BMR × activity multiplier. Your BMR (Basal Metabolic Rate) is the calories you burn at complete rest — calculated using the Mifflin-St Jeor formula. The activity multiplier ranges from 1.2 (sedentary) to 1.9 (very active athlete). For example: BMR of 1,600 × 1.55 (moderate activity) = TDEE of 2,480 calories.

Eat 300–500 calories below your TDEE for gradual, sustainable weight loss. A 500-calorie daily deficit equals roughly 0.5kg lost per week. Most NHS and health guidelines recommend losing no more than 0.5–1kg per week. Extreme deficits cause muscle loss and are hard to sustain.

BMR (Basal Metabolic Rate) is the calories you burn at complete rest — just to keep your organs functioning. TDEE is your BMR multiplied by an activity factor to account for movement throughout the day. BMR is always lower than TDEE. For example, a person with a BMR of 1,600 who exercises moderately has a TDEE around 2,480. You should always use TDEE (not BMR) to calculate your calorie targets.

The NHS figure of 2,000 calories (women) and 2,500 (men) is a population average — a general guide for food labelling. Your personal TDEE depends on your actual weight, height, age, and activity level. Taller, heavier, younger, or more active people have higher TDEEs. Using your personalised TDEE is far more accurate than the generic NHS figure for weight management.

Common reasons: your activity level is overestimated (sedentary means desk job with no exercise, not "I walk sometimes"), calorie tracking is inaccurate (liquid calories, cooking oils, and sauces are often missed), or your TDEE has dropped as you have lost weight and your deficit is now smaller than you think. Recalculate your TDEE every 4–6 weeks and track food accurately for 2 weeks before adjusting.

TDEE calculators are estimates — typically accurate to within 100–200 calories for most people. The Mifflin-St Jeor formula used here is the most validated method for general adults. Accuracy decreases at extremes of body composition (very muscular or very high body fat). Use your calculated TDEE as a starting point, track your actual weight for 2–3 weeks, and adjust by 100–200 calories if results do not match expectations.