Calculator
Maintenance calories
Your maintenance calories are the amount you can eat in a day without gaining or losing weight — also called TDEE. Everything below comes from your own figures; nothing is sent anywhere.
2,600kcal / day
- Resting burn (BMR)
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- Everything else
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- Lose 0.5 kg/week, eat
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- Gain 0.25 kg/week, eat
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An estimate stacked on an estimate: Mifflin–St Jeor carries about ±10%, and the activity factor is a blunt instrument. Treat it as a starting point and correct it against three weeks of your own weight data.
How this is worked out
Your resting burn comes from the Mifflin–St Jeor equation, published in 1990 and still the one most clinicians use:
Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161That figure is then multiplied by an activity factor between 1.2 and 1.9 to cover movement, exercise and the energy spent digesting food. The result is your maintenance.
Why the measured number beats the calculated one
The activity multiplier is where the error creeps in — the gap between "lightly active" and "moderately active" is close to 300 kcal a day, and most people genuinely cannot tell which describes them. Eating consistently for three weeks and watching your weekly average weight will tell you more than any formula.The full method is here.
The deficit calculator takes this number and turns it into a daily target and a finish date.