BMI Calculator
BMI calculator: body mass index from weight and height in lb/in or kg/cm, with the WHO weight category for adults.
IMC = mh²
How to use this calculator
- Choose the quantity you want under “Solve for”.
- Type the known values and pick their units: any combination works.
- The result updates as you type. Open “Show the steps” to see the substitution.
Body mass index is weight in kilograms divided by height in meters squared. The calculator accepts pounds and inches and converts them automatically.
BMI is a quick screening measure; it does not distinguish muscle from fat and is not used the same way for children, athletes or pregnant people.
For healthy adults; it is not a diagnosis. Talk to a doctor or dietitian about your personal situation.
Formula
IMC = mh²
| Symbol | Quantity | Units |
|---|---|---|
| m | Weight | kg, g, mg, µg, t, lb, oz, st, US ton, ct, Da |
| h | Height | m, km, cm, mm, µm, nm, pm, Å, in, ft, yd, mi, nmi, au, ly |
| BMI | Body mass index | — |
Worked example
Given: m = 154.324 lb · h = 68.8976 in
BMI = mh²
Result: BMI = 22.8571
Frequently asked questions
What is a healthy BMI?
For adults, the WHO classifies 18.5–24.9 as normal weight, 25–29.9 as overweight and 30 or more as obesity.
How is BMI calculated in pounds and inches?
BMI = 703 × weight (lb) ÷ height (in)². The calculator does this conversion for you.