Height and weight calculator

Calculate adult BMI from height and weight

Use this height and weight calculator to estimate adult body mass index in either standard or metric units. Enter height and weight once, switch between tabs when needed, and see the BMI value and adult category update immediately.

Calculator

Choose your input units

Use standard inputs for feet, inches, and pounds, or switch to metric for centimeters and kilograms. The tool keeps the same measurement when you change tabs.

Standard BMI uses height in total inches and weight in pounds, then applies the 703 conversion factor.

Result

Adult BMI result

BMI is a screening measure based on height and weight. It does not directly measure body fat or body composition.

Body mass index

23.6

Healthy

Based on the current entry, the adult BMI category is Healthy. This result falls in the standard adult healthy BMI range used for general screening.

Standard adult BMI categories used by this calculator.
BMI CategoryBMI Range
UnderweightUnderweight
Below 18.5
HealthyHealthy
18.5 - 24.9
OverweightOverweight
25.0 - 29.9
ObesityObesity
30.0 or above

How It Works

BMI formulas in standard and metric units

The calculator supports both common input systems. Each tab feeds the same underlying height and weight values, so the BMI result stays consistent.

Standard formula

Convert the height entry to total inches, then multiply the pounds-based fraction by 703.

total inches = (feet x 12) + inches
BMI = (pounds / (total inches x total inches)) x 703

Metric formula

Convert centimeters to meters first, then divide kilograms by height in meters squared.

height in meters = centimeters / 100
BMI = kilograms / (height in meters x height in meters)

Examples

Worked examples

These examples match the expected outputs for the first version of this tool.

Example 1: 5 ft 9 in and 160 lb

total inches = (5 x 12) + 9
total inches = 69
BMI = (160 / (69 x 69)) x 703
BMI = 23.6
category = Healthy

Example 2: 175 cm and 72 kg

height in meters = 175 / 100
height in meters = 1.75
BMI = 72 / (1.75 x 1.75)
BMI = 23.5
category = Healthy

FAQ

Frequently asked questions

Quick answers for the main interpretation and unit-switching questions that come up with BMI calculators.

Who is this BMI calculator for?

This version is for adults. BMI categories on this page use the standard adult ranges for underweight, healthy, overweight, and obesity.

Does BMI measure body fat directly?

No. BMI is a quick screening number based on height and weight. It does not directly measure body fat, muscle mass, bone density, or body composition.

Can I switch between metric and standard units?

Yes. The tool keeps one normalized height-and-weight model behind the form, so switching tabs updates the display without changing the underlying measurement.

What does Reset do?

Reset restores the default sample entry for this page, which is 5 ft 9 in and 160 lb. You can then replace it with your own numbers.

Sources

Reference links

These sources define the adult BMI calculator framing and category ranges used on this page.