Estimating daily calorie needs
The Mifflin–St Jeor equation estimates resting metabolic rate using age, height, weight and sex. An activity multiplier approximates total daily energy expenditure.
Worked example
Example: results vary substantially with activity. Compare the sedentary and moderately active options rather than treating a single number as exact.
Assumptions and limitations
This is a rough adult estimate, not medical or dietary advice. Needs vary with health, pregnancy, age and other factors.
How to use this calculator
Enter the requested values, check the units, and press Calculate now. Adjust one input at a time to compare scenarios. The result updates only when you press the button again.
For educational purposes only. Verify important financial or health decisions with a qualified professional.
How calorie needs are estimated
Resting energy expenditure uses the Mifflin–St Jeor equation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) + 5 for males or −161 for females. An activity multiplier estimates daily maintenance calories.
Frequently asked questions
Are these exact daily calorie needs?
No. Actual energy expenditure varies with activity, body composition and other individual factors. Use the result as a starting estimate.
Can I use this calculator for free?
Yes. CalcTrustHub calculators are free to use and do not require an account. Results are estimates based on your inputs.
How to interpret a maintenance estimate
The Mifflin–St Jeor equation estimates resting energy expenditure using age, height, weight and the selected sex-based equation. An activity multiplier estimates total daily energy needs. Real needs can differ because of individual physiology, training and daily movement.
Should I treat the number as an exact target?
No. It is a starting estimate, not a prescription. Individual requirements and changes over time vary.