BMR Formula Comparison
See why different BMR calculators give you different results. Compare 4 scientific formulas at once.
Required for Katch-McArdle and Cunningham formulas.
Why Do BMR Calculators Give Different Results?
BMR formulas use different mathematical models and were developed on different populations. Mifflin-St Jeor is the modern standard, while Harris-Benedict is older and tends to overestimate. Katch-McArdle and Cunningham use lean body mass, making them more accurate for athletic individuals.
Which BMR Formula Should I Trust?
For most people, Mifflin-St Jeor is the best choice. If you know your body fat percentage, use Katch-McArdle. The difference between formulas is typically 50-150 calories, which is within the margin of error. Use the average as your starting point.