Sri Lanka BMI Calculator (Asian Cut-Offs)
Work out your Body Mass Index and read it on the Asian cut-offs Sri Lanka's Ministry of Health actually uses, where overweight starts at BMI 23, not 25, next to the WHO scale, plus your healthy weight range for your height.
How it works
Body Mass Index is the Quetelet index: your weight in kilograms divided by the square of your height in metres.
BMI = weight (kg) ÷ height (m)²
If you enter imperial units the tool converts them first, height in metres is (feet × 12 + inches) × 0.0254 and weight in kilograms is pounds × 0.45359237. The result is then cross-checked against the imperial form BMI = 703 × lb ÷ inches², which agrees to within about 0.01%. BMI is age- and sex-independent, so the formula is the same for everyone; age and sex here only trigger guidance notes.
The difference this tool makes is in the classification. Global calculators use the WHO international bands, normal 18.5–24.9, overweight 25.0–29.9, obese 30.0 and above. But South Asians develop higher body fat and higher cardiometabolic risk at a lower BMI, so the WHO 2004 expert consultation defined lower action points (23.0 and 27.5) for Asian populations, and the WHO/IASO/IOTF Asia-Pacific guidance set the working bands used across South Asian clinical practice. Sri Lanka's Ministry of Health adopts these for national non-communicable-disease management.
The Sri Lankan / Asian bands this tool applies as the primary result:
- Below 18.5 : Underweight
- 18.5 – 22.9 : Normal
- 23.0 – 24.9 : Overweight (increased risk)
- 25.0 – 29.9 : Obese I (moderate)
- 30.0 and above : Obese II (severe)
The healthy weight range for your height comes straight from the Normal band: the lower limit is 18.5 × height² and the upper limit is 22.9 × height², both in kilograms. If your BMI is in the Normal band you are within range; otherwise the tool reports the exact number of kilograms between your weight and the nearest edge of the healthy range. Nothing is sent to a server, the whole calculation runs in your browser.
Worked examples
Frequently asked questions
Sources & references
- WHO Expert Consultation: Appropriate BMI for Asian populations (The Lancet, 2004; 363:157–163)
- WHO/IASO/IOTF: The Asia-Pacific Perspective: Redefining Obesity and its Treatment (WPRO, 2000)
- Ministry of Health, Sri Lanka: Guideline on Management of Overweight and Obesity among Adults (2018)
- WHO: Obesity (standard international BMI classification)
The cut-offs on this page were last cross-checked against the sources above on 2026-07-08. BMI classifications change rarely; the page is reviewed whenever the WHO or Sri Lanka's Ministry of Health revises its guidance.
Related tools
Comments & feedback
Spotted a bug or want an improvement? Tell us, our team reviews every comment, and good ideas get built. Comments are public and anonymous.
Found a bug, edge case, or want to suggest an improvement?
Email me at [email protected] , most fixes ship within 24 hours.