BMI Calculator

Under Singapore's Asian-Pacific guidelines, a healthy BMI is 18.5 to 22.9. A BMI of 23 to 27.4 is in the overweight range with moderate health risk, and 27.5 and above is classified as obese with high risk. This is stricter than the WHO international range, where healthy runs up to 24.9. The calculator lets you switch between both so you can compare.^{[1, 3]}

The BMI chart maps your BMI to a weight category and its health risk: underweight, healthy, overweight and obese. Your own row is highlighted as you adjust your numbers, and the balloon shows the same result as your altitude. You will also see the healthy weight range for your exact height.

The BMI formula and the healthy range are the same for women and men, so 18.5 to 22.9 applies to both in Singapore. Sex matters for your daily calorie estimate, because women and men have different basal metabolic rates. That is why the calculator asks for it.^{[1, 4]}

Yes. It works in centimetres and kilograms by default, and you can switch to feet, inches and pounds with one tap. Your numbers convert automatically, and your BMI stays the same either way because the calculation always uses kilograms and metres behind the scenes.

Research shows Asian populations face a higher risk of type 2 diabetes and heart disease at lower BMI values than Western populations. Singapore's health guidelines therefore flag moderate risk from BMI 23 and high risk from 27.5, compared with WHO's 25 and 30. HiAltitude uses Asian-Pacific cutoffs by default and lets you switch to WHO for comparison.^{[1, 2]}

We estimate your basal metabolic rate with the Mifflin-St Jeor equation, using your sex, age, height and weight, then multiply it by your activity level to estimate the calories that keep your weight steady. The gentle adjustment shows a modest deficit or surplus depending on where your balloon is flying. These are estimates for healthy adults, not a prescription.^[4]