Free online Calorie Calculator
Three simple steps
- Choose the equation category, then enter your adult age, weight, and height using the selected units.
- Pick the activity description that best matches your usual week, not just your most active day.
- Read estimated maintenance energy and the resting-energy estimate beneath it.
Understand your result
This is an adult maintenance-energy estimate. It combines the Mifflin–St Jeor resting-energy equation with an activity multiplier. It is a starting estimate, not a prescribed food intake or a weight-loss plan.
Worked example
For the male equation at age 30, 70 kg, and 175 cm: resting estimate = 10×70 + 6.25×175 − 5×30 + 5 = 1,648.75 kcal/day. With the sedentary factor of 1.2, estimated maintenance = 1,648.75 × 1.2 ≈ 1,979 kcal/day.
Choose an activity factor
| Usual activity | Multiplier |
|---|---|
| Little exercise | 1.2 |
| Light: roughly 1–3 days/week | 1.375 |
| Moderate: roughly 3–5 days/week | 1.55 |
| Very active: roughly 6–7 days/week | 1.725 |
| Physical work or intense training | 1.9 |
Exercise duration, intensity, occupation, and individual variation matter; days per week are only rough descriptors. Choosing a higher factor increases the estimate.
Equation and limitations
Resting estimate = 10×weight(kg) + 6.25×height(cm) − 5×age + equation constant. The constants are +5 for the male equation and −161 for the female equation. Those are the categories in the original equation, not a complete description of physiology. The tool accepts whole-number adult ages from 18 to 120; that input range does not mean the equation is equally accurate for everyone.
When to seek individual advice
Do not use this estimate to plan nutrition for children, pregnancy or breastfeeding, an eating disorder, or a condition requiring medical nutrition care. Energy needs can differ considerably from a formula. A qualified clinician or dietitian can interpret your circumstances.
Formula reference
Mifflin et al. (1990), “A new predictive equation for resting energy expenditure in healthy individuals” — PubMed. Activity factors are additional approximations, not personal measurements.