Our free BMI calculator — Body Mass Index calculator — helps you quickly determine whether your weight is in a healthy range for your height. BMI is one of the most widely used screening tools in medicine and public health, used by doctors and health organizations across the USA and Canada.

This BMI calculator supports both imperial units (feet, inches, and pounds) and metric units (centimeters and kilograms). After calculating your BMI, you will see your BMI value, your weight category, and the healthy weight range for your height. A visual BMI gauge helps you understand where you fall on the scale at a glance.

How to Use the BMI Calculator

Calculating your BMI takes less than a minute:

1. Select your unit system — Imperial (lbs / ft, in) or Metric (kg / cm).
2. Enter your height and weight.
3. Enter your age and sex for additional context.
4. Click Calculate BMI to see your result, category, and healthy weight range.

When Should You Use a BMI Calculator?

Use the BMI calculator as a general health screening tool to understand whether your current weight is within a healthy range. In particular, it is useful before a doctor’s appointment as a quick self-check. Furthermore, many health and wellness programs use BMI as a baseline measurement to track progress over time.

However, it is important to understand the limitations of BMI. While BMI is a convenient screening tool, it does not directly measure body fat. Athletes with high muscle mass may have a high BMI despite low body fat. Use BMI alongside other assessments for a complete picture of health.

Understanding Your BMI Result

Here is how to interpret your BMI score and what it means for your health:

• Under 18.5 — Underweight: May indicate nutritional deficiency or an underlying health condition. Consult your doctor.
• 18.5 to 24.9 — Normal weight: Generally associated with the lowest health risk for most people.
• 25.0 to 29.9 — Overweight: May increase risk of heart disease, type 2 diabetes, and other conditions.
• 30.0 and above — Obese: Associated with significantly increased health risks. Weight loss through diet and exercise is strongly recommended.

Frequently Asked Questions About the BMI Calculator

What is a healthy BMI for adults?

For adults 20 and older, a BMI between 18.5 and 24.9 is considered normal weight and is generally associated with the lowest health risks. BMI categories are the same for both men and women.

Is BMI accurate for everyone?

BMI has known limitations. It may overestimate body fat in athletes and muscular individuals, and underestimate it in older adults who have lost muscle mass. It is also not recommended as the sole health measure for children, pregnant women, or the elderly.

How is BMI calculated?

BMI = weight (kg) / height (m)². In imperial units: BMI = (weight in pounds × 703) / height in inches². For example, a person who is 5’9″ and weighs 170 lbs has a BMI of approximately 25.1.

Related Calculators

Furthermore, you might find these related tools useful: Body Fat Calculator — Ideal Weight Calculator — BMR Calculator — Calorie Calculator

Disclaimer: BMI is a screening tool and not a diagnostic measure. It does not account for muscle mass, bone density, or fat distribution. Consult a healthcare professional for a full health assessment.