BMI calculator

Enter your height and weight to get your BMI, the category it falls in, and the weight range considered healthy for your height.

Metric only.

Metric only.

  1. CategoryHealthy weight
  2. Healthy-range weight for your heightBMI 18.5 to 24.9125.3 to 168.6 lb
  3. Underweightbelow 18.5
  4. Healthy weight18.5 to 24.9
  5. Overweight25 to 29.9
  6. Obesity30 and above
Your BMI 24.4

BMI is a screening measure, not a diagnosis. It doesn't account for muscle, frame or body composition. Talk to a clinician about what's healthy for you.

Last updated 13 Sep 2026.

How to use it

  1. Pick your units.
  2. Enter your weight and height. Use the pound and feet fields for imperial, the kilogram and centimetre fields for metric.
  3. Read your BMI and its category, and the weight range that would put you in the healthy band.

Worked example

165 lb at 5 ft 9 in.

That’s 74.84 kg and 1.7526 m. BMI = 74.84 ÷ 1.7526² = 24.4, in the healthy range. For that height, 18.5 to 24.9 corresponds to 125.3 to 168.6 lb.

How it's calculated

BMI = weight in kilograms ÷ (height in metres)²

Imperial inputs are converted exactly first: 1 lb = 0.45359237 kg, 1 in = 0.0254 m.

Categories follow the WHO and CDC adult cut-offs: under 18.5 underweight, 18.5 to 24.9 healthy, 25 to 29.9 overweight, 30 and above obesity. The healthy-range weights are the weights that give a BMI of 18.5 and 24.9 at your height.

FAQ

Is BMI accurate for me?

It's a population screening tool. It over-reads for muscular people and under-reads for older adults who have lost muscle. Waist circumference and body-fat measurements add information a single number can't; a clinician can interpret them together.

Do the cut-offs change for age or sex?

Not for adults over 20. Children and teens use age- and sex-specific percentile charts instead, so this calculator isn't for them. Some guidance uses lower cut-offs, 23 and 27.5, for people of South Asian descent.

What does the healthy range mean?

The weights at your height that fall between BMI 18.5 and 24.9. It's a wide band on purpose; where you sit within it is much less important than trends over time and other health measures.

How much should I change my weight to move categories?

Every BMI point is about 3 kg or 6.6 lb for someone of average height. The range row shows the exact weights for the healthy band at your height.