Calorie Calculator

How many calories a day?

Enter your details to estimate maintenance calories, using the Mifflin-St Jeor equation.

For adults aged 19–78, the age range studied in the original equation. Not for pregnancy, breastfeeding, eating-disorder treatment or a medically prescribed diet.

Sex
Age (years)
Height
Weight
Activity level

Daily Calories

Maintenance —

Enter your details and choose your activity level to see an estimate.

Understand your result

This is a rough maintenance-energy estimate, not a weight-loss prescription. Activity categories include both exercise and daily movement; choosing by exercise days alone can overestimate or underestimate your needs. Adjustments for weight change should be individualized.

How this works

Mifflin–St Jeor estimates resting energy in kcal/day: 10 × weight (kg) + 6.25 × height (cm) − 5 × age, then +5 for males or −161 for females. This calculator multiplies that result by an approximate activity factor: 1.2, 1.375, 1.55, 1.725 or 1.9. These heuristic activity factors are separate from the original resting-energy equation.

Read about fat loss and weight loss.

Method and sources

General educational estimates, not medical advice. Calculations run in your browser; this calculator does not save or send your entered measurements. Site analytics and advertising may still operate separately. Method and code checked on 27 September 2026; not clinically reviewed.