This calorie calculator estimates how many calories you need per day to lose, maintain or gain weight. It uses the Mifflin–St Jeor equation and your activity level to find your maintenance calories, then shows daily targets for every common goal.
| Goal | Calories / day |
|---|---|
| Extreme weight loss (−2 lb/week) | – |
| Weight loss (−1 lb/week) | – |
| Mild weight loss (−0.5 lb/week) | – |
| Maintain weight | – |
| Mild weight gain (+0.5 lb/week) | – |
| Weight gain (+1 lb/week) | – |
Targets below 1,500 kcal (men) or 1,200 kcal (women) are flagged rather than shown — sustained intake under those levels should be medically supervised.
What Is a Calorie Calculator?
A calorie calculator estimates the daily energy your body needs. It starts from your basal metabolic rate (BMR) — the calories you burn at complete rest — scales it by activity to get maintenance calories (your TDEE), then adjusts for your goal: subtract for weight loss, add for weight gain. Roughly 500 kcal/day of deficit equals about a pound of body weight per week, because a pound of body fat stores about 3,500 kcal. This page belongs to our Health Calculators collection.
Worked Examples (Verified)
- Man, 30, 80 kg, 180 cm, moderately active: BMR = 1,780 kcal → maintenance 2,759 kcal/day. Weight loss target: 2,259; mild loss: 2,509; mild gain: 3,009.
- Woman, 30, 65 kg, 165 cm, lightly active: BMR = 1,370 kcal → maintenance 1,884 kcal/day. Weight loss target: 1,384.
The formula used is Mifflin–St Jeor, the most accurate of the common BMR equations: men — 10×weight(kg) + 6.25×height(cm) − 5×age + 5; women — the same, minus 161 instead of plus 5. If you only want the resting number, our BMR Calculator isolates it; for expenditure analysis by activity, the TDEE Calculator goes deeper.
How Many Calories Should You Eat?
- Losing weight: start with maintenance − 500 (≈1 lb/week). Smaller deficits are slower but far easier to sustain, and sustainability decides results.
- Maintaining: eat at your TDEE and monitor for 2–3 weeks; adjust by ±100–200 kcal if the trend drifts.
- Gaining muscle: maintenance + 250–500 with adequate protein — set your protein target with the Protein Calculator.
- Know your composition: at the same weight, more muscle means a higher BMR. Our Body Fat Calculator estimates your split between fat and lean mass.
Why Estimates Need Real-World Adjustment
Every calorie formula is an estimate — individual metabolism varies ±10% or more, activity multipliers are coarse, and food labels are imperfect. Treat the number as a starting point: follow it consistently for 2–3 weeks, watch the weight trend, and nudge by 100–200 kcal. Also note exercise calories are already inside the activity multiplier — do not add your workout burn on top unless you selected "sedentary".
Related Tools
- TDEE Calculator — total daily energy expenditure
- BMR Calculator — resting metabolic rate
- Body Fat Calculator — body composition
- Protein Calculator — daily protein target
Frequently Asked Questions
How many calories should I eat to lose weight?
About 500 kcal below your maintenance level for roughly 1 lb per week. The calculator above gives your personal maintenance and the loss targets from it.
How accurate is this calorie calculator?
Mifflin–St Jeor predicts BMR within about ±10% for most adults. Real-world tracking and small adjustments beat any formula's precision.
Is 1,200 calories a day enough?
It is the commonly cited minimum for women (1,500 for men) for unsupervised dieting. Below that, nutrient adequacy and muscle loss become concerns — this calculator flags sub-floor targets instead of recommending them.
Do I add exercise calories to my target?
Not if you picked an activity level above sedentary — exercise is already counted in the multiplier. Double-counting is the most common reason calorie plans stall.
What is the difference between BMR and TDEE?
BMR is rest-only burn; TDEE is BMR × activity — your actual daily total. Weight change is driven by intake vs. TDEE.
Is this calorie calculator free?
Yes — free, instant, no sign-up. It provides general estimates, not medical advice.