Enter your height and weight. Instantly see your Body Mass Index and healthy weight range.
Enter your height and weight, in inches and pounds or in centimetres and kilograms, and the page returns your BMI, the band it falls in, and the weight range that would put you in the middle band for your height. The age field is context only; BMI is not adjusted for age in adults.
Measure height without shoes and weight at the same time of day for comparisons over time. Morning weight and evening weight differ by a couple of pounds in most people, which is enough to move a BMI at a boundary.
70 inches and 160 lb:
| Measure | Value |
|---|---|
| Height in metres | 1.778 m |
| Weight in kilograms | 72.6 kg |
| BMI | 22.96 |
| Band | Normal weight |
| Weight range for the band | about 129–174 lb |
The band edges are fixed numbers: 18.5, 25, 30. At this height the whole healthy range spans 45 pounds, which is a wide corridor. Someone at the top of it and someone at the bottom have the same BMI label and very different bodies.
BMI is weight divided by height squared. It is a screening tool, and it was designed to describe populations rather than individuals. Its weakness is that it cannot tell muscle from fat: a lean, heavily trained person can read as overweight, and someone with low muscle mass can read as normal while carrying a high body-fat percentage. Around the boundaries, a single point means very little.
The bands come from the World Health Organization's adult classification, which uses 18.5, 25, and 30 as the cut-offs for underweight, normal, overweight and obese. Those thresholds are the same for men and women and do not change with age, which is both the tool's convenience and its limit: body composition shifts with age at the same BMI.
Use it as one number among several. Waist circumference, how clothes fit, strength and cardiovascular fitness all say something BMI cannot. If your BMI sits well inside a band and has been stable, it is telling you what you already know.
Poorly. Muscle is denser than fat, so a muscular person can be classified as overweight at a low body-fat percentage.
The formula and the bands are the same. Body composition differs, which is one reason the number is less informative for individuals than for groups.
Children are assessed on age-and-sex percentiles rather than fixed cut-offs, so this calculator does not apply to them.
A common guide is under 40 inches for men and under 35 for women, though the exact thresholds vary by guidance body. Waist adds information BMI cannot.
A range is more useful than a target number. Small, sustained changes in weight and activity do more than chasing a decimal.
Adult cutoffs are CDC’s. This tool is not CDC’s calculator, and it is not for ages 2 to 19.
Last updated: November 2, 2026. Reviewed by David Liu.