Guide · Updated November 2026 · How we check our numbers
How Many Calories Do I Need? BMR, TDEE and Macros
Your daily calorie needs depend on your body size, age, sex and activity. Calculators estimate them in two steps.
Step 1: BMR
Basal metabolic rate is what your body burns at rest. The Mifflin-St Jeor equation is one of the most accurate for most adults:
- Men: 10 × kg + 6.25 × cm − 5 × age + 5
- Women: 10 × kg + 6.25 × cm − 5 × age − 161
A 30-year-old man weighing 80 kg at 180 cm: 800 + 1,125 − 150 + 5 = 1,780 calories.
Step 2: activity
Multiply BMR by an activity factor — 1.2 (sedentary), 1.375 (light), 1.55 (moderate), 1.725 (very active) or 1.9 (extra active). At 1.55, our example needs about 2,759 calories a day to maintain weight.
Step 3: macros
Protein and carbohydrates have 4 calories per gram, fat has 9. A balanced 30/40/30 split of 2,200 calories is about 165 g protein, 220 g carbs and 73 g fat.
Changing your weight
A rough rule is that 3,500 calories equals about a pound of body weight, so a 500-calorie daily deficit is about 1 lb a week. Real progress slows over time, and the CDC suggests aiming for a gradual 1–2 lb a week.
These are estimates. Track your weight for a few weeks and adjust — and ask a healthcare professional for personal advice.
Try the calculators
This guide is general information, not professional advice.