Why BMI misclassifies athletes
Weight over height squared cannot tell muscle from fat, and at this build it says so loudly.
Daily energy need
3,859–4,397kcal
The range is the answer. The formulas disagree by 283 kcal (13%) before the extremely active multiplier of 1.9 is applied.
BMI
29.2
Overweight
By WHO Asian-population cutoffs: High risk
Healthy range for this height: 63.3–85.2 kg
Protein
72–108g/day
General health
Computed on lean body mass (90 kg). The RDA floor is 0.8 g/kg; many bodies recommend more for older adults.
Every formula, side by side
- Mifflin-St Jeor2,031 kcal
The most widely recommended of the three for general use.
- Harris-Benedict (revised)2,168 kcal
Older, and tends to read higher than Mifflin-St Jeor.
- Katch-McArdle2,314 kcal
Uses lean mass rather than total weight, so it is the better estimate when body composition is known — especially at either extreme of muscularity.
Height
185.0 cm · 6' 1"
Weight
100.0 kg · 220.5 lb (15st 10lb)
What to read before using any of this
Read this
The formulas disagree by 283 kcal (13%)
Resting expenditure comes out between 2031 and 2314 kcal depending on which standard equation you use, and both are fitted to population averages rather than to you. After the activity factor the plausible range is 3859-4397 kcal. Any calculator that reports a single number to the calorie is implying precision that does not exist.
What to do: Treat the range as the answer. Pick a point inside it, hold it for a few weeks, and adjust based on what actually happens to your weight — measured response beats any formula.
Note
The activity multiplier is the largest source of error
The multipliers run from 1.2 to 1.9, so the choice between two adjacent bands moves the estimate by roughly 355 kcal — more than the disagreement between the formulas. Most people overestimate their own activity level.
What to do: If you are between two bands, take the lower one and adjust upward from evidence.
Note
Not medical advice
These are population-level estimates from formulas fitted to population averages. They are not medical advice and know nothing about your health, medication, pregnancy, or history. BMI in particular is not a measure of health. Talk to a clinician or a registered dietitian before acting on any of it.
Run your own numbers
Use the form on the home page, or call the API or MCP server. This page is available as markdown.
Related examples
Not medical advice, and not a substitute for talking to a clinician or a dietitian. Produces population-level estimates from formulas fitted to population averages; it knows nothing about an individual's health, medication, pregnancy, or history. Does not diagnose anything, and BMI in particular is not a measure of health.