Calorie Calculator
Estimate BMR and daily maintenance calories with the Mifflin-St Jeor equation, plus loss and gain targets.
Processed locally in your browser — nothing is uploaded.
Calorie Calculator
Enter your height, weight, and age to estimate daily calories.
About Calorie Calculator
Uses the Mifflin-St Jeor equation — the standard clinicians reach for — to estimate your basal metabolic rate, then multiplies by an activity factor (1.2 sedentary up to 1.9 extra active) for daily maintenance calories. Loss and gain targets apply the common ±250 and ±500 kcal adjustments, roughly a quarter and half kilogram per week.
Common uses
- Set a starting calorie target for a cut or bulk
- Sanity-check what a fitness app assigned you
- See how much an activity-level change moves your maintenance number
Example
Input
Male, 30y, 80 kg, 180 cm, moderately active
Output
BMR 1,780 kcal · maintenance 2,759 kcal · loss target 2,259 kcal
Limitations
- Population-average math — individual metabolism commonly varies by ±10% or more.
- Not calibrated for children, pregnancy, or very high muscle mass; adjust from real-world results over a few weeks.
Frequently asked questions
What formula does this calorie calculator use?
The Mifflin–St Jeor equation: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age, plus 5 for males or minus 161 for females. Studies have found it the most reliable of the common BMR equations for adults, which is why clinicians favor it over the older Harris–Benedict.
What's the difference between BMR and maintenance calories?
BMR is what your body burns at complete rest; maintenance (often called TDEE) adds daily movement by multiplying BMR by an activity factor from 1.2 (sedentary) through 1.375, 1.55, and 1.725 up to 1.9 (extra active). Maintenance is the number to eat at to hold your current weight.
How many calories should I cut to lose a pound a week?
About 500 kcal below maintenance per day, the deficit behind the loss target shown — roughly 0.5 kg or 1 lb per week. The −250 kcal mild-loss target halves that pace, which is often easier to sustain.
Is my personal health data stored when I use this calculator?
No. Your age, weight, height, and sex are processed only in your browser — nothing is transmitted, logged, or kept after you leave the page.
How accurate are calorie calculators?
They're population-average estimates: individual metabolisms commonly differ from the prediction by ±10% or more. Treat the number as a starting point and adjust based on how your weight actually trends over two to four weeks.