Find how many calories you should eat per day to lose, maintain, or gain weight — based on your BMR, activity level, and the Mifflin-St Jeor equation.
It depends on your age, sex, height, weight, and activity level — there's no single number that applies to everyone. As a general reference, most adult women maintain their weight eating 1,800–2,400 calories per day, and most adult men around 2,200–3,000. This calculator gives you a number personalized to your own stats rather than a population-wide average.
BMR is the number of calories your body burns just to stay alive at complete rest — keeping your heart beating, lungs breathing, and brain functioning, with zero additional movement. It typically makes up 60–70% of your total daily calorie burn, making it the single biggest piece of the puzzle.
(w = weight in kg, h = height in cm, a = age in years)
TDEE is your BMR multiplied by an activity factor, giving your true daily maintenance calories — the number you'd eat to keep your weight stable.
| Activity level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Desk job, little to no exercise |
| Light | 1.375 | Light exercise 1–3 days/week |
| Moderate | 1.55 | Moderate exercise 3–5 days/week |
| Active | 1.725 | Hard exercise 6–7 days/week |
| Very active | 1.9 | Physical job or training twice a day |
One pound of body fat is roughly equivalent to 3,500 calories. A calorie deficit means consistently eating below your TDEE — a 500-calorie daily deficit works out to about 3,500 calories per week, producing an estimated 1 pound of fat loss weekly. The same math works in reverse for a calorie surplus to gain weight.
Research comparing common BMR formulas has found Mifflin-St Jeor to be more accurate than the older Harris-Benedict equation for most healthy adults, which is why it's the default in most modern calorie calculators. That said, no formula is perfectly accurate for every individual — actual metabolism can vary 5–15% or more due to muscle mass, genetics, and other factors. Track your weight for 2–3 weeks at your calculated target and adjust by ±100 calories/day if your real-world results don't match.
It depends on your age, sex, height, weight, and activity level, but most adult women maintain their weight around 1,800 to 2,400 calories per day, and most adult men around 2,200 to 3,000. To lose about 1 pound per week, eat roughly 500 calories per day below your personal maintenance level (your TDEE), and to gain, eat roughly 500 above it.
TDEE is the total number of calories your body burns in a full day, including resting metabolism, digestion, and all physical activity. It's calculated by multiplying your BMR (calories burned at rest) by an activity multiplier that reflects how much you move — from 1.2 for a sedentary lifestyle up to 1.9 for a very physically demanding one.
BMR is the number of calories your body needs just to stay alive at complete rest — keeping your heart beating, lungs breathing, and organs functioning, with no additional movement. It typically accounts for 60 to 70 percent of total daily calorie burn, and is most commonly estimated using the Mifflin-St Jeor equation.
One pound of body fat is roughly equivalent to 3,500 calories. A calorie deficit means consistently eating fewer calories than your body burns (your TDEE) — a daily deficit of about 500 calories works out to roughly 3,500 calories per week, producing an estimated 1 pound of weight loss weekly. This is an estimate, not an exact guarantee, since individual metabolism varies.
Research comparing common BMR formulas has found the Mifflin-St Jeor equation to be more accurate than the older Harris-Benedict equation for most healthy adults, which is why it's the default formula in most modern calorie calculators. No formula is perfectly accurate for every individual — actual metabolism can vary by 5 to 15 percent or more due to factors like muscle mass and genetics.