Calorie Calculator
Estimate how many calories you burn each day (TDEE) and how many to eat to maintain, lose or gain weight, using the Mifflin-St Jeor equation. US or metric units.
Free · No sign-upHow to use Calorie Calculator
- 1. Choose US or metric units, then enter your sex, age, height and weight.
- 2. Pick the activity level that matches a typical week — most people with a desk job and a few workouts are lightly or moderately active.
- 3. Read your BMR and maintenance calories (TDEE), with the formula worked out, and the daily targets for mild, normal or faster weight loss or gain.
- 4. Try another formula (Katch-McArdle if you know your body fat %), then copy the numbers or a share link.
Frequently asked questions
How many calories should I eat a day?
Start from your maintenance calories (TDEE): the calories you burn at your activity level. Eating about 500 kcal a day less loses roughly 1 lb (0.45 kg) a week; 500 more gains about the same. This calculator shows those targets for you.
What is the Mifflin-St Jeor equation?
It estimates your basal metabolic rate (BMR): 10 × weight in kg + 6.25 × height in cm − 5 × age, then + 5 for men or − 161 for women. It’s the equation most dietitians use because it’s the most accurate for most adults. TDEE is BMR × an activity factor from 1.2 to 1.9.
What is the difference between BMR and TDEE?
BMR is what your body burns at complete rest just to stay alive. TDEE (total daily energy expenditure) adds everything you do in a day — walking, work, exercise and digestion — so it’s the number to base your diet on.
Which activity level should I choose?
Sedentary (×1.2) is a desk job with little exercise; lightly active (×1.375) is exercise 1–3 days a week; moderately active (×1.55) is 3–5 days; very active (×1.725) is hard exercise 6–7 days; extra active (×1.9) is a physical job plus training. If unsure, pick the lower one.
Is it safe to eat below 1,200 calories?
Most guidelines advise women not to go below about 1,200 kcal a day and men below about 1,500 kcal without medical supervision, which is why those targets are flagged. The calculator isn’t for pregnancy, breastfeeding, children or medical conditions — ask a doctor or dietitian.
How accurate is a calorie calculator?
Equations like Mifflin-St Jeor are usually within about 10% for most people, but genetics, muscle mass and how you rate your activity all matter. Use the result as a starting point, track your weight for 2–3 weeks, and adjust by 100–200 kcal.