BMI · BMR · TDEE · Body Fat Calculator — WHO Asia-Pacific & Mifflin-St Jeor
Free body composition calculator: BMI with WHO Asia-Pacific thresholds (23 / 27.5), Mifflin-St Jeor BMR, Harris-Benedict comparison, TDEE with WHO/FAO/UNU activity factors, and US Navy Hodgdon-Beckett body fat formula. Pure browser, zero tracking.
Pure browser. Zero upload. Your measurements never leave this tab.
| WHO Global | — |
| WHO Asia-Pacific | — |
| Healthy range (Global) | — |
| Healthy range (Asian) | — |
| BMI Prime | — |
| Ponderal Index | — |
›Formula
BMI = weight (kg) / height (m)²
WHO 2000 + 2004 Asia-Pacific Consultation
Why WHO Asia-Pacific cutoffs matter
The default BMI cutoffs (18.5 / 25 / 30) were calibrated on European populations. WHO's 2004 Asia-Pacific Expert Consultation reviewed the evidence and concluded that Asian populations carry the same body-fat percentage and metabolic disease risk at lower BMI values, so the action lines should be 23 (overweight) and 27.5 (obese). Singapore, Hong Kong, and mainland China all reference these cutoffs in their public-health guidance. This calculator shows both classifications side by side.
Mifflin-St Jeor vs Harris-Benedict
The 1919 Harris-Benedict equation overstates BMR for most modern adults by 5–10%. A 2005 American Dietetic Association systematic review found Mifflin-St Jeor (1990) the most accurate of the major BMR formulas, with 82% of estimates falling within ±10% of measured values. We default to Mifflin-St Jeor and show the 1984 Roza-Shizgal revision of Harris-Benedict alongside it so you can see how much the formula choice matters.
Activity multipliers from WHO/FAO/UNU
TDEE multipliers across online calculators vary wildly (1.2 to 2.0+), which produces up to 400 kcal/day of disagreement for the same person. The 1.2 / 1.375 / 1.55 / 1.725 / 1.9 values used here come from the WHO/FAO/UNU 2004 Human Energy Requirements consultation (Technical Report 935), with the original activity descriptions next to each multiplier.
US Navy body fat formula (Hodgdon-Beckett)
The US Navy method, published in 1984 by Hodgdon and Beckett (NHRC reports 84-11 and 84-29), needs only a soft tape measure and is the official body-composition test for the DoD (Instruction 1308.3). It estimates body density from neck and waist circumference (and hip for women) and converts to %BF via the Siri equation. Standard error of estimate is ±3.5% (men) and ±3.7% (women) compared to underwater weighing — accurate enough for most uses, with the caveat that very lean or very heavy bodies fall outside the calibration range.
FAQ
- Why does this calculator show two BMI categories?
- Because risk thresholds differ by ancestry. WHO Global cutoffs were calibrated on European data; the 2004 WHO Asia-Pacific consultation found that Asian populations reach the same body-fat and metabolic-disease risk at lower BMI, so the overweight line is 23 and the obese line is 27.5. Showing both makes the difference explicit instead of hiding it behind a single number.
- Which BMR formula should I use, Mifflin-St Jeor or Harris-Benedict?
- Mifflin-St Jeor (1990) is the more accurate choice for most modern adults — a 2005 ADA systematic review found it hits within ±10% of indirect-calorimetry values about 82% of the time, beating Harris-Benedict by roughly 5 percentage points. We default to MSJ but display the 1984 Roza-Shizgal revision of Harris-Benedict alongside so you can see the gap.
- How accurate is the US Navy body fat formula?
- Standard error of estimate is about ±3.5% for men and ±3.7% for women compared to hydrostatic (underwater) weighing — accurate enough for most fitness and military uses, less reliable at extreme leanness or extreme obesity. It is the official DoD body-composition test (Instruction 1308.3) and only needs a soft tape measure.
- Is my data sent anywhere?
- No. Every calculation runs entirely in your browser via JavaScript. No height, weight, age, or measurement values are uploaded or logged.
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