Calorie Calculator
See how many calories you need each day to lose weight, maintain, or build muscle — free, no sign-up needed.
Fill in your details to see your daily calorie targets.
How your calorie needs are calculated
This calculator uses the Mifflin–St Jeor equation, the formula dietitians most commonly rely on for estimating basal metabolic rate (BMR) — the energy your body burns at rest:
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Your BMR is then multiplied by an activity factor to estimate your total daily energy expenditure (TDEE):
| Activity level | Multiplier | Typical week |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | Light exercise 1–3 days/week |
| Moderately active | 1.55 | Moderate exercise 3–5 days/week |
| Very active | 1.725 | Hard exercise 6–7 days/week |
| Extra active | 1.9 | Physical job plus training |
Worked example: a 30-year-old man, 175 cm and 75 kg, has a BMR of 10×75 + 6.25×175 − 5×30 + 5 = 1,699 kcal. If he exercises 3–5 days a week (×1.55), his maintenance is ≈ 2,633 kcal/day — about 2,133 to lose ~0.5 kg/week, or ~2,933 to gain muscle in a lean surplus.
What to do with your number
A target only works if you track against it. Split your calories sensibly across the day — our free macro calculator turns the number into protein, carb, and fat targets — and weigh in weekly, adjusting by 100–200 kcal if your trend is off. If you want to understand the resting-energy half of the math, see the BMR calculator.
Calories during Ramadan and fasting
Fasting changes when you eat, not how much your body needs. During Ramadan, aim to reach your daily target across suhoor and iftar: anchor suhoor with protein and slow carbs, break the fast with fluids and dates, and keep the main iftar meal balanced rather than compressed into one oversized plate. The same logic applies to 16:8 and other protocols — our 16:8 beginner's guide covers the details.
Frequently asked questions
How many calories should I eat to lose weight?
A deficit of about 500 kcal below your maintenance level leads to roughly 0.5 kg (1 lb) of weight loss per week. Use the calculator above to find your maintenance calories, then subtract 500 — but avoid going below 1,200 kcal/day without medical guidance.
What formula does this calorie calculator use?
It uses the Mifflin–St Jeor equation, widely considered the most accurate formula for estimating resting energy needs, multiplied by an activity factor between 1.2 (sedentary) and 1.9 (extra active).
How accurate are calorie calculators?
Equations estimate within about ±10% for most people. Treat the number as a starting point: track your intake and weight for 2–3 weeks, then adjust by 100–200 kcal if your real-world trend differs from the goal.
Do my calorie needs change during Ramadan?
Your total daily energy needs stay roughly the same — what changes is the eating window. Aim to reach your normal daily target across suhoor and iftar, anchoring each meal with protein and fluids rather than compressing everything into one large meal.
This tool provides general estimates, not medical advice. Consult a professional before major dietary changes.
Hit your target every day
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