Calorie Calculator
Estimate how many calories you burn in a day, plus targets for losing or gaining weight.
How to use
- Pick your sex and enter age, height and weight.
- Choose how active you are on a typical week.
- See your maintenance calories plus lose/gain targets.
How the Calorie Calculator works
Estimates the daily calorie intake needed to maintain, lose or gain weight, based on your body metrics and activity level.
Resting energy use is estimated from weight, height, age and sex, then scaled by an activity multiplier to give maintenance calories. Goal adjustments shift that figure up or down.
maintenance = BMR × activity factor
Worked example
If maintenance is 2,400 kcal, a moderate cut of 20% targets about 1,920 kcal a day — roughly a pound of fat loss per week.
Things worth knowing
- A pound of body fat holds roughly 3,500 kcal, so a 500 kcal daily deficit approximates a pound a week. Real loss is messier because water weight and adaptation intervene.
- Weight loss slows as you get lighter: a smaller body needs fewer calories, so the same intake becomes a smaller deficit over time.
- Very low intakes are hard to sustain and tend to cost lean mass alongside fat.
Frequently asked questions
What formula does this use?
It uses the Mifflin-St Jeor equation for BMR, multiplied by an activity factor to estimate total daily energy expenditure.
How many calories to lose weight?
A deficit of about 500 calories a day is a common target for roughly half a kilogram of loss per week.
Why has my weight loss stalled?
Usually a mix of a smaller body needing less energy, portion creep, and water retention masking real fat loss. Recalculate your target at your current weight.
Do calories from different foods count the same?
For energy balance, broadly yes. For appetite, satiety and body composition, no — protein and fibre keep you fuller for the same calories.