BMI Calculator for Adults: Body Mass Index in lb/ft or kg/cm

How to use this tool

Choose your units

Pick US (feet, inches, pounds) or metric (centimeters, kilograms), and the standard WHO categories or the lower Asian cut-offs.

Enter height and weight

Type your height and weight. Your BMI updates as you type.

Read your result

See your BMI, its category on the gauge, and the healthy weight range for your height.

Example

5 ft 9 in and 170 lb, a result right on a category line.

Input

Units: feet and pounds
Height: 5 ft 9 in
Weight: 170 lb

Result

BMI: 25.1
Category: Overweight (25 – 29.9)
Healthy weight for this height: about 125 – 169 lb

Two pounds lighter, the same person reads 24.8 and lands in the healthy range. A result this close to a cut-off says very little on its own.

How BMI is calculated

BMI is your weight divided by your height squared. In metric, that's kilograms ÷ meters². In US units, it's pounds × 703 ÷ inches². Someone who is 5 ft 10 in (70 inches) and weighs 165 lb has a BMI of 165 × 703 ÷ 4,900 ≈ 23.7.

Adult BMI categories

The CDC and the World Health Organization use the same ranges for adults 20 and older, for both men and women:

Underweight: below 18.5
Healthy weight: 18.5 to 24.9
Overweight: 25 to 29.9
Obesity: 30 or higher (often split into class 1 at 30–34.9, class 2 at 35–39.9 and class 3 at 40+)

What BMI can and can't tell you

BMI is a quick screening number, not a diagnosis. It's useful across large groups of people, but it doesn't measure body fat directly, and it can't tell muscle from fat. Athletes often score as 'overweight' while being very fit, and older adults can have a 'healthy' BMI while carrying more body fat than it suggests.

Children and teens use BMI-for-age percentiles instead of these cut-offs, and BMI isn't used during pregnancy. Waist size, blood pressure, blood sugar and family history all matter too. If you're concerned about your weight or health, talk to a doctor.

Healthy weight for your height

These ranges are the weights that give a BMI of 18.5 to 24.9 for adults. The last column is where a BMI of 30, the obesity line, starts.

4 ft 10 in: 89 to 119 lb (obesity from 144 lb)
5 ft 0 in: 95 to 128 lb (from 154 lb)
5 ft 2 in: 101 to 136 lb (from 164 lb)
5 ft 4 in: 108 to 145 lb (from 175 lb)
5 ft 6 in: 115 to 154 lb (from 186 lb)
5 ft 8 in: 122 to 164 lb (from 197 lb)
5 ft 10 in: 129 to 174 lb (from 209 lb)
6 ft 0 in: 136 to 184 lb (from 221 lb)
6 ft 2 in: 144 to 194 lb (from 234 lb)
6 ft 4 in: 152 to 205 lb (from 246 lb)

Healthy weight in kilograms

150 cm: 41.6 to 56.0 kg
155 cm: 44.4 to 59.8 kg
160 cm: 47.4 to 63.7 kg
165 cm: 50.4 to 67.8 kg
170 cm: 53.5 to 72.0 kg
175 cm: 56.7 to 76.3 kg
180 cm: 59.9 to 80.7 kg
185 cm: 63.3 to 85.2 kg
190 cm: 66.8 to 89.9 kg

BMI for South Asian and other Asian adults

A 2004 World Health Organization expert consultation found that many Asian populations carry higher health risks, such as type 2 diabetes, at lower BMIs than European populations. It suggested extra action points at 23 and 27.5. Several countries in Asia use 23 as the start of 'overweight' for this reason.

This calculator shows the standard WHO categories. If you're of South Asian, Chinese, Japanese or other Asian descent, treat a BMI from 23 to 24.9 as a reason to look at waist size and other health markers, not as fully in the clear.

Common errors

Height in meters in the centimeter box

1.75 isn't read as 175 cm. Type 175, otherwise no result shows.

All the inches in the feet box

5 ft 9 in goes in two boxes: 5 and 9. Typing 69 as feet is far outside a human height, so nothing is calculated.

Pounds typed into the kilogram box

Switch units before you type. 170 entered as kg instead of lb more than doubles the BMI.

Frequently asked questions

What is a healthy BMI?

For adults, a BMI of 18.5 to 24.9 is considered a healthy weight by the CDC and the World Health Organization.

How do I calculate BMI in pounds and inches?

Multiply your weight in pounds by 703, then divide by your height in inches squared. For example, 150 lb at 65 inches is 150 × 703 ÷ 4,225 ≈ 25.0.

Is BMI different for men and women?

No. Adults use the same formula and categories. Women tend to have more body fat than men at the same BMI, which is one of the limits of the measure.

Is BMI accurate for athletes?

Not always. Muscle is denser than fat, so very muscular people can have a high BMI without excess fat. A waist measurement or body fat test gives a better picture.

Can children use this BMI calculator?

No. Children and teens are assessed with BMI-for-age percentiles, which account for growth. Ask a pediatrician or use the CDC's child and teen BMI calculator.

Is a BMI of 25 overweight?

Yes. For adults, 25 to 29.9 is classed as overweight and 30 or more as obesity. A BMI of exactly 25 sits right on the line, so waist size and other health markers tell you more.

What is a healthy weight for my height?

Any weight that gives a BMI of 18.5 to 24.9. At 5 ft 6 in that's about 115 to 154 lb; at 170 cm it's about 53.5 to 72 kg. Enter your height and the calculator shows your own range.

Is BMI different for Asians?

The formula is the same, but many health bodies in Asia use lower cut-offs: healthy is 18.5 to 22.9, overweight from 23 and obesity from 27.5. Switch the calculator to 'Asian cut-offs' to use them.

BMI Calculator for Adults