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Calorie needs explained

Calorie calculator

Calculate how many calories you burn per day based on your stats and activity level, and instantly see what you need to maintain, lose or gain weight.

Calculate your calorie needs

Enter your details and pick the activity level that best matches your week.

What are your calorie needs?

Your calorie needs are the amount of energy your body uses per day. They consist of your resting metabolic rate (BMR) - the energy you burn doing nothing - plus everything you burn on top of that through movement, exercise and digestion. Together that is your TDEE (Total Daily Energy Expenditure), also known as your maintenance calories.

How the calculation works

This calculator uses the Mifflin-St Jeor equation, shown in research to be the most reliable estimate of resting metabolic rate in adults. The result is multiplied by an activity factor that matches how much you move.

BMR (male) = 10 × weight + 6.25 × height - 5 × age + 5
BMR (female) = 10 × weight + 6.25 × height - 5 × age - 161

Losing or gaining weight

To lose weight, a deficit of roughly 500 kcal per day is a common guideline: that works out to about half a kilogram of fat loss per week. For muscle gain, a modest surplus of 200 to 300 kcal is typically used, combined with strength training and sufficient protein.

Caveats to keep in mind

Every formula is an estimate. Use the result as a starting point and adjust based on what your weight and energy actually do in practice.

  • Muscle mass, hormones and genetics create individual differences no formula can capture.
  • Honestly estimating your activity level is the biggest source of error: when in doubt, pick one level lower.
  • Weigh yourself weekly for a few weeks and adjust your intake in steps of 100 to 200 kcal.
  • Ask a qualified coach or dietitian for personal advice if you have medical conditions or specific goals.