BMI Calculator
Use this free BMI calculator (Body Mass Index calculator) to check whether your weight falls in a healthy range for your height. It works for men and women in US or metric units and shows your BMI category plus a healthy weight range.
How BMI is calculated
Body Mass Index (BMI) is a body mass index measure that divides weight by the square of height. In metric units:
In US (imperial) units, the formula includes a conversion factor of 703:
BMI chart — adult categories
This BMI chart follows World Health Organization ranges used by most body mass index BMI calculators for adults (including BMI calculator women / female checks):
| BMI range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obesity |
BMI for women and men
The same adult BMI formula is used for women and men. A women's BMI calculator and a men's BMI calculator use identical cutoffs; differences in body composition mean BMI is only a screening tool. Pair it with our Body Fat Calculator, BMR Calculator, or Calorie / TDEE Calculator for a fuller picture.
Limitations of BMI
BMI does not distinguish muscle from fat, so athletes can show a high BMI with low body fat. It also may not fully account for age, ethnicity, or pregnancy. Use this body index chart as a starting point, not a diagnosis.
Frequently Asked Questions
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered a healthy weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obesity.
Is BMI the same for women and men?
Yes — adult BMI cutoffs are the same for women and men. The formula does not change for a BMI calculator female or male check; only body composition interpretation may differ.
How do I calculate BMI manually?
Divide your weight in kilograms by height in meters squared, or use BMI = 703 × weight (lb) / height (in)² for US units. This BMI calculator does that instantly.
Does BMI work if I am muscular?
BMI can overestimate body fat in muscular people because muscle weighs more than fat. Consider a body fat percentage estimate alongside BMI.