Formula
The reference weight is a BMI of 22 at the same height. The page then finds the age, from 18 to 80, whose reference resting energy is closest to yours:
Reference kg = 22 × (height in meters)²
A higher body weight raises the Mifflin result, which can match a younger reference because the equation subtracts 5 kcal per year. That is a property of the comparison, not a measured metabolic age.
Assumptions
- Both sides use Mifflin–St Jeor.
- The reference body has BMI 22 and your height.
- Ages outside 18 to 80 are not searched.
Worked example
The male equation at age 30, 71.28 kg, and 180 cm has a comparison age of 30 years.
Input definitions
- Comparison age
- The reference age whose BMI-22 resting estimate is closest to yours.
Limitations
This is an informational estimate for adults. It is not a diagnosis, a diet plan, or a training prescription. Pregnancy, illness, and medication can change what is appropriate.
Questions
Is this a lab metabolic age?
No. It only compares two Mifflin–St Jeor results. No breathing test is involved.
Why can a heavier person look younger here?
The equation gives heavier bodies a higher resting number, and younger reference ages also have a higher number.