What this tool does
Estimate adult resting energy expenditure and maintenance calories from sex used by the equation, age, weight, height and activity level.
How to use it
- Choose the equation sex and activity category.
- Enter age from 18 to 120, weight in kilograms and height in centimetres.
- Review resting, maintenance and ±250 kcal planning values as estimates rather than prescriptions.
Formula and method
Mifflin–St Jeor resting energy = 10×kg + 6.25×cm − 5×age + 5 for men or −161 for women. Maintenance multiplies this by 1.2, 1.375, 1.55, 1.725 or 1.9. The loss and gain figures subtract or add 250 kcal.
Worked example
A 30-year-old man at 70 kg and 175 cm has an estimated resting value of 1,649 kcal. With moderate activity factor 1.55, maintenance rounds to 2,556 kcal/day.
Common uses
- Creating an initial maintenance estimate
- Comparing activity-level assumptions
- Providing a calorie target to a separate macro conversion
Limitations
Predictive equations can differ from measured energy use. Health, body composition, medication, pregnancy, ageing and actual activity change needs. The ±250 figures are arithmetic scenarios, not medical or weight-change advice.
FAQ
Which activity level should I choose?
Choose the category closest to your sustained usual activity and compare nearby levels if uncertain; short-term exercise does not always represent the whole week.
Is this basal metabolic rate measured?
No. It is a resting-energy prediction from population research, not indirect calorimetry performed on you.