Calorie Calculator
Find out exactly how many calories you need each day to lose weight, stay the same, or build muscle — based on the Mifflin-St Jeor equation.
Maintenance calories
0 kcal/day
Eat this much to stay at your current weight.
Calorie targets by goal
Daily macros for maintenance
Protein is set at 1.8 g per kg of body weight to support muscle retention. Fat is 25% of calories. Carbohydrates fill the remainder.
Hit your numbers without the guesswork
Track calories, macros and progress automatically with a food-logging app.
See recommended tracker →Disclaimer: This calculator provides estimates for healthy adults based on the Mifflin-St Jeor equation. It is not medical advice. Consult a physician or registered dietitian before starting any weight-management programme, especially if you are pregnant, breastfeeding, under 18, or managing a medical condition.
How this calorie calculator works
Your daily calorie needs depend on two things: the energy your body burns at complete rest (your Basal Metabolic Rate, or BMR) and how much you move on top of that. Together they give your Total Daily Energy Expenditure (TDEE) — the number of calories you need to maintain your current weight.
Step 1 — Resting energy (BMR)
This tool uses the Mifflin-St Jeor equation, which the American Dietetic Association identified as the most reliable standard formula for healthy adults:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Step 2 — Activity multiplier
Your BMR is multiplied by an activity factor that reflects how much you move during a typical week.
| Activity level | Multiplier | Typical profile |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | Light exercise 1–3 days per week |
| Moderately active | 1.55 | Moderate exercise 3–5 days per week |
| Very active | 1.725 | Hard exercise 6–7 days per week |
| Extra active | 1.9 | Physical job or twice-daily training |
Step 3 — Adjust for your goal
A deficit of roughly 500 kcal per day produces about 0.5 kg (1 lb) of weight loss per week. A surplus of 300 kcal per day supports lean muscle gain while limiting fat accumulation. Anything more aggressive is harder to sustain and increases the risk of muscle loss.
Frequently asked questions
How many calories should I eat to lose 1 lb per week?
One pound of body fat contains roughly 3,500 calories, so a daily deficit of about 500 kcal produces approximately 1 lb (0.45 kg) of loss per week. Subtract 500 from your maintenance calories to get that target.
Most health authorities recommend losing no more than 0.5–1% of body weight per week to preserve muscle mass and keep the change sustainable.
Is the Mifflin-St Jeor equation accurate?
It's considered the most accurate general-purpose formula for healthy adults, typically landing within 10% of measured resting energy expenditure. No equation can account for individual differences in muscle mass, genetics, or metabolic adaptation, so treat the result as a starting point and adjust based on real-world results after two to three weeks.
Should I eat back the calories I burn during exercise?
Usually not. Your activity multiplier already accounts for planned exercise. Eating back every calorie a fitness tracker reports often cancels out your deficit, since trackers tend to overestimate burn. Only adjust upward if you're losing weight faster than intended or feeling persistently fatigued.
How much protein do I actually need?
Research supports roughly 1.6–2.2 g of protein per kg of body weight per day for people who train and want to preserve or build muscle. This calculator uses 1.8 g/kg as a sensible middle ground. Older adults and those in a steep deficit may benefit from the higher end.
Why is my result different from another calculator?
Different tools use different equations — Harris-Benedict, Katch-McArdle, or Cunningham — and different activity multipliers. Katch-McArdle, for example, uses body fat percentage and is more accurate for lean, muscular people. Results within 100–200 kcal of each other are normal.
Can I use this calculator if I'm pregnant or under 18?
No. Pregnancy, breastfeeding, adolescence, and certain medical conditions all change energy requirements in ways this equation doesn't capture. Please work with a doctor or registered dietitian instead.