Calorie calculator

How this calorie calculator works

1. BMR. We estimate your basal metabolic rate (the energy you burn at rest) with the Mifflin-St Jeor equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then +5 for men or −161 for women.
2. TDEE. We multiply BMR by an activity factor from 1.2 (sedentary) to 1.9 (extremely active) to estimate your total daily energy expenditure. See the TDEE calculator for a full breakdown.
3. Goal. For fat loss we subtract 250–500 calories, which works out to roughly 0.5–1 lb (0.25–0.5 kg) per week for most people. For muscle gain we add about 250 calories to keep fat gain modest.

How to use your number

Treat the result as a starting point, not a prescription. Eat at that target for two to three weeks, weigh yourself several mornings per week, and look at the weekly average. If the average isn't moving the way you want, adjust by 100–200 calories and reassess. Real bodies vary; equations are typically within about 10% for most adults.

Calories matter most, but protein decides how much of the weight you lose is fat versus muscle. Pair your calorie target with a protein target from the protein calculator, and keep lifting weights two or three times per week if you can.

Common mistakes

• Overestimating activity. Most people with a desk job and three workouts a week are "lightly active", not "very active". When in doubt, pick the lower level.
• Cutting too aggressively. Large deficits are hard to sustain and tend to cost muscle. A steady −500 beats a crash diet you quit in week two.
• Not tracking weekends. Two loose days can erase five careful ones. A plan that includes foods you actually like is easier to stick with.

If you want a plan built around these numbers, our guide on meal plans and workout plans together shows how to combine them.