Energy
The sex constant
The same three terms feed both versions; only the constant differs. A male adds 5, a female subtracts 161, a gap of 166 kcal for identical body data.
The Formula
BMR = base + s, where base = 10w + 6.25h - 5a
The same three terms feed both versions; only the constant differs. A male adds 5, a female subtracts 161, a gap of 166 kcal for identical body data.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| base | Weight, height and age terms combined | kcal per day | For 70 kg, 175 cm and 30 years this comes to 1643.75 kcal. |
| s | Sex constant | kcal per day | Plus 5 for a male, minus 161 for a female. It is a fitted constant, not a value judgement. |
What Each Symbol Means
basekcal per day
Weight, height and age terms combined
For 70 kg, 175 cm and 30 years this comes to 1643.75 kcal.
skcal per day
Sex constant
Plus 5 for a male, minus 161 for a female. It is a fitted constant, not a value judgement.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate bmr page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate BMR, filed under Health. Every number the guide produces comes from substituting into this one line.