Calorie calculator
Calorie Calculator
Find how many calories you should eat a day to lose weight, maintain, or build muscle. Enter your details for your BMR, TDEE (maintenance calories), and a goal-by-goal breakdown — free, no signup, using the Mifflin-St Jeor equation.
How to use your results
The calculator gives you five numbers that matter. Your TDEE is your maintenance level — eat that to stay the same weight. Everything else is that number plus or minus a deficit or surplus:
- Mild weight loss (−250 kcal) — slow, easy to sustain, barely noticeable hunger.
- Weight loss (−500 kcal) — the standard recommendation, ~0.5 kg / 1 lb per week.
- Aggressive loss (−1,000 kcal) — faster but harder to hold and risks muscle loss.
- Lean muscle gain (+250 kcal) — a small surplus to build muscle without excess fat.
The formula behind it
This uses the Mifflin-St Jeor equation, the modern standard for resting energy expenditure: for men, BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5; for women, the same but −161. Your BMR is then multiplied by an activity factor from 1.2 (sedentary) to 1.9 (athlete) to get your TDEE. Want just one part? Use the dedicated TDEE calculator, BMR calculator, or calorie deficit calculator.
Calories are only half the job
A target is useless if you can't stick to it. The hard part is knowing how many calories are actually on your plate — which is exactly what the MyPlate appautomates: snap a photo or scan a barcode and it logs calories and macros against this target for you. See also your macro split and the guide to how many calories you should eat.
Frequently asked questions
How many calories should I eat a day?
It depends on your age, sex, height, weight, and activity level. The calculator computes your BMR with the Mifflin-St Jeor equation, multiplies by your activity factor to get your TDEE (maintenance calories), then adjusts for your goal. As rough averages, women maintain around 2,000 kcal/day and men around 2,500 — but your personal number can differ by several hundred calories.
How does a calorie calculator work?
It estimates two things: how many calories you burn at rest (BMR) and how many you burn in total per day (TDEE = BMR × activity factor). To lose weight you eat below your TDEE; to gain, above it. This calculator shows your maintenance number plus mild, standard, and aggressive weight-loss targets and a lean-gain target.
How accurate is this calorie calculator?
The Mifflin-St Jeor equation predicts resting energy expenditure within about 10% for most people — it is the formula most dietitians use today. Real needs vary with muscle mass, genetics, and non-exercise activity, so treat the number as a starting point and adjust based on 2–3 weeks of real results.
Is this calorie calculator free?
Yes — it is completely free and needs no signup. To then track the calories you actually eat against your target, the MyPlate app logs meals by photo or barcode automatically, also free on iOS and Android.
Should I eat back exercise calories?
The activity multiplier in this calculator already includes your typical exercise, so you generally should not add extra calories for planned workouts on top. If you selected "sedentary" but did a big one-off session, a partial add-back (about half the burned calories) is a reasonable adjustment.