The contenders
Harris-Benedict (1919, revised 1984): the original. Overestimates BMR by ~5% on modern populations.
Mifflin-St Jeor (1990): calibrated on a modern sample. Accepted by the American Dietetic Association as the most accurate for non-athletes.
Katch-McArdle: uses lean body mass. Most accurate if you know your body fat percentage.
Which to use
Default to Mifflin-St Jeor. It's what our calculator uses.
If you know your body fat %, Katch-McArdle is slightly better for lean, muscular people.
Any formula is a starting estimate. Track your weight for 2 weeks, then adjust.
