Calorie Calculator

Calculating daily calorie needs is the foundation of any nutrition plan. Total Daily Energy Expenditure (TDEE) is the number of calories you actually burn — eating at TDEE maintains weight, below loses, above gains. The Mifflin-St Jeor equation is the most accurate of the common BMR formulas.

BMR and TDEE formulas

Basal Metabolic Rate (BMR) is calories burned at complete rest. Mifflin-St Jeor for men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: same but − 161 instead of + 5. TDEE = BMR × activity factor (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, 1.9 very active).

When to use this calculator

Use it as the starting point for any cut, bulk, or maintenance phase. Eat at TDEE for two weeks and weigh yourself daily — if your weight is stable, your TDEE is accurate. Adjust by 250-500 calories/day to lose or gain about 0.5-1 lb/week. Aggressive deficits over 1,000 cals/day below TDEE work short-term but typically cause muscle loss and rebound.

Worked example

A 30-year-old woman, 5'6", 150 lbs (68 kg), 168 cm, moderately active. BMR: 10 × 68 + 6.25 × 168 − 5 × 30 − 161 = 1,419. TDEE: 1,419 × 1.55 = 2,200 calories/day. To lose 1 lb/week, eat ~1,700/day. To gain muscle, eat ~2,500/day with high protein.

Limits and assumptions

Daily calories start from the Mifflin-St Jeor BMR for your sex (+5 for men, −161 for women), weight, height and age, with imperial inputs converted to kilograms and centimetres first, then multiplied by one of the fixed activity factors from 1.2 (sedentary) to 1.9 (very active). The result is rounded to the nearest calorie.

The activity factors are standard presets and cannot be customised, and the formula knows nothing about body composition, thyroid function or medication. Treat the number as a starting estimate: eat at it for two or three weeks and adjust by what the scale does.

Frequently asked questions