Basal Metabolic Rate (Harris-Benedict, Women)

The women's arm of the 1984 Roza and Shizgal revision: $447.593 + 9.247m + 3.098h - 4.330a$. A 60 kg woman of 165 cm aged 40 gets $447.593 + 554.82 + 511.17 - 173.2 = 1340$ kcal/day. The coefficients are genuinely different from the men's set rather than a constant offset, which is why the two live on separate pages here: there is no single sex factor that converts one into the other.

The difference between the two equations is mostly a proxy for body composition rather than for sex as such. Women carry a higher proportion of fat at the same mass and height, and fat is metabolically quieter than muscle, so the mass coefficient is smaller. That also means the equation misreads anyone whose composition is unusual for their inputs, in either direction. A muscular athlete will come out low, and someone with a high fat fraction will come out high.

The same caveats as the men's version apply. It runs roughly 5 percent above measured resting expenditure on average, drifts further in obesity, and predates the population now using it by a century. Mifflin-St Jeor is the better current fit and is what most clinical nutrition guidance recommends. And in either equation the answer is a resting rate, which becomes a daily requirement only after multiplying by an activity factor that is itself a rough guess.