How to calculate your daily calorie needs
- 1.
Choose units and enter your data
Pick metric or imperial, then enter your sex, age, weight and height.
- 2.
Pick your activity level
Choose the option that best matches your usual week, including both exercise and a physical job.
- 3.
Set a goal
Maintain, lose (a deficit of 250-750 kcal) or gain weight (a surplus of 250-500 kcal).
- 4.
Read the result
You see BMR, TDEE, your calorie target with the expected weekly change, and a protein, carb and fat split in grams.
How the calculation works
BMR (basal metabolic rate) is the energy your body uses at complete rest. The calculator uses the Mifflin-St Jeor equation, considered the most accurate for healthy adults:
- men: BMR = 10 × weight [kg] + 6.25 × height [cm] - 5 × age + 5,
- women: BMR = 10 × weight [kg] + 6.25 × height [cm] - 5 × age - 161.
TDEE (total daily energy expenditure) is BMR multiplied by an activity factor from 1.2 (sedentary) to 1.9 (very active). Imperial values are converted first: 1 lb = 0.4536 kg and 1 in = 2.54 cm.
Example: a 35-year-old man, 5 ft 10 in (178 cm), 180 lb (81.6 kg), exercising 3-5 times a week: BMR ≈ 1,758 kcal, TDEE ≈ 1,758 × 1.55 ≈ 2,725 kcal. To lose weight he would aim for about 2,225 kcal a day. A 30-year-old woman, 168 cm and 65 kg with light activity has a BMR of 1,389 kcal and a TDEE of about 1,910 kcal.
Calorie deficit and the pace of weight loss
One kilogram of body fat stores roughly 7,700 kcal (about 3,500 kcal per pound). A daily deficit of 500 kcal therefore gives about 0.45 kg (1 lb) less per week, and 250 kcal about 0.2 kg (0.5 lb). A safe pace is usually 0.5-1% of body weight per week. Do not eat below your BMR without medical supervision. A very large deficit raises the risk of muscle loss and fatigue, and the weight often comes back.
The result is an estimate that can be off by about 10% for any individual. Track your weight for 2-3 weeks (a weekly average, not single weigh-ins) and adjust the target by 100-200 kcal if needed.
Macros: protein, carbs and fat
Protein and carbohydrates provide 4 kcal per gram, fat 9 kcal per gram. The "balanced" split (20/50/30) is close to general dietary guidelines. When cutting, more protein (1.6-2.2 g per kg, or about 0.7-1 g per lb of body weight) helps preserve muscle and keeps you fuller. The high-protein and low-carb options set protein at 30% of calories. The calculator shows protein per kilogram or per pound so you can check it falls in this range.
Activity levels explained
| Level | Factor | Typical week |
|---|---|---|
| Sedentary | 1.2 | desk job, no planned exercise |
| Light | 1.375 | 1-3 workouts or brisk walks a week |
| Moderate | 1.55 | 3-5 workouts a week |
| Active | 1.725 | hard training 6-7 days a week |
| Very active | 1.9 | physical job plus daily training |
People often overestimate their activity. If you are unsure, pick the lower level and adjust after a few weeks. To check whether your weight is in a healthy range, use the BMI calculator.
Frequently asked questions
How many calories should I eat to lose weight?
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What is the difference between BMR and TDEE?
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Which formula is the most accurate?
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Can I use pounds and feet?
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How much protein do I need?
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Why am I not losing weight on the calculated calories?
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