Health note
This calculator gives an estimate for adults. It is not a diagnosis, prescription, or substitute for advice from a qualified health or nutrition professional.
Health calculator
Calorie calculator
Estimate resting energy, maintenance calories, and a daily planning target with metric or imperial units.
Interpretation limits
Actual needs can differ because of medication, hormones, illness, body composition, training load, pregnancy, breastfeeding, and metabolic adaptation.
Estimate daily calories
Method and formulas
Mifflin-St Jeor resting energy
RMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + constantThe published equation uses +5 for the male constant and -161 for the female constant.
Maintenance calories
maintenance = RMR × activity factorThe activity factor is a planning multiplier, not a direct measurement of activity.
Goal target
target = maintenance + calorie adjustmentGoals are planning examples. They do not prescribe a diet or guarantee weight change.
Activity factors
| Sedentary | 1.2 | Mostly seated daily routine. Factor 1.2. |
|---|---|---|
| Lightly active | 1.375 | Light movement or exercise a few days a week. Factor 1.375. |
| Moderately active | 1.55 | Moderate exercise or active routine. Factor 1.55. |
| Very active | 1.725 | Hard exercise or demanding daily activity. Factor 1.725. |
| Extremely active | 1.9 | Very hard training or physical work. Factor 1.9. |
Goal options
Maintain weight
0 kcal
No calorie adjustment.
Small deficit
-250 kcal
-250 kcal per day.
Moderate deficit
-500 kcal
-500 kcal per day.
Small surplus
250 kcal
+250 kcal per day.
Examples
Metric maintenance
male equation, age 30, 80 kg, 180 cm, moderate activity, maintain weight
resting energy = 1,780 kcal/day, maintenance = 2,759 kcal/day, target = 2,759 kcal/day
Imperial maintenance
female equation, age 35, 143 lb, 5 ft 5 in, light activity, maintain weight
resting energy is about 1,345 kcal/day; maintenance is about 1,849 kcal/day
Below resting energy warning
sedentary activity with a -500 kcal goal
the calculator shows a warning when the target falls below estimated resting energy
FAQ
Is this a medical recommendation?
No. It is an estimate for adults and should not replace professional advice.
Why does the form ask for an equation version?
The Mifflin-St Jeor equation has two published versions. The choice only selects the mathematical constant used in that equation.
Can actual calorie needs differ?
Yes. Body composition, medications, hormones, training, illness, and weight change can all affect needs.
Why warn when the target is below resting energy?
Targets below estimated resting energy can be inappropriate without individual clinical context.