HEALTH CALCULATOR
BMI Calculator
Calculate your body mass index (BMI) from height and weight. Choose metric or US units to view your adult BMI category, estimated healthy weight range, and visual BMI insights.
Calculate Your BMI
Enter your height and weight to calculate adult BMI.
Within the commonly used adult healthy-weight screening range.
Category
Adult BMI categories are screening ranges and should be interpreted in context.
Healthy Weight Reference
Mathematical range corresponding to BMI 18.5–24.9.
BMI Category Gauge
BMI Categories
Healthy Weight Range
This is a mathematical reference range based on the standard adult BMI screening range. It is not an individualized medical recommendation.
How Weight Changes BMI
The chart keeps your entered height constant and shows how BMI changes as weight changes.
What Is BMI?
Body mass index, or BMI, is a screening calculation that compares weight with height. It is commonly used to group adults into broad weight-status categories: underweight, healthy weight, overweight, and obesity.
BMI is not a direct measurement of body fat or a diagnosis. Muscle mass, age, body composition, and other individual factors can affect how a result should be interpreted.
How to Calculate BMI
The formula depends on the measurement system, but both methods estimate the same BMI value.
Metric BMI Formula
Divide weight in kilograms by height in meters squared.
US BMI Formula
Divide weight in pounds by height in inches squared, then multiply by 703.
For example, an adult who weighs 70 kg and is 1.75 m tall has a BMI of approximately 22.9.
BMI Categories for Adults
These commonly used adult screening ranges help describe a BMI result. They are not a complete assessment of health.
| BMI Range | Weight Status | General Interpretation |
|---|---|---|
| Below 18.5 | Underweight | Below the adult reference range |
| 18.5–24.9 | Healthy weight | Within the adult reference range |
| 25.0–29.9 | Overweight | Above the adult reference range |
| 30.0–34.9 | Obesity, Class 1 | Adult obesity screening range |
| 35.0–39.9 | Obesity, Class 2 | Adult obesity screening range |
| 40.0 or higher | Obesity, Class 3 | Adult obesity screening range |
What Does Your BMI Mean?
Your result places your height and weight into one of the adult screening categories above. The calculator also estimates the weight range corresponding mathematically to a BMI of 18.5–24.9 at your entered height.
This range is a reference calculation, not an individualized target or medical recommendation. Interpret the result alongside other relevant health information.
Healthy Weight Range by Height
The weight associated with a given BMI changes with height. The table provides approximate weights at the lower and upper boundaries of the adult reference range.
| Height | Weight at BMI 18.5 | Weight at BMI 24.9 |
|---|---|---|
| 5'0" (152 cm) | 43 kg (95 lb) | 58 kg (128 lb) |
| 5'4" (163 cm) | 49 kg (108 lb) | 66 kg (145 lb) |
| 5'8" (173 cm) | 55 kg (122 lb) | 75 kg (165 lb) |
| 5'10" (178 cm) | 59 kg (130 lb) | 79 kg (174 lb) |
| 6'0" (183 cm) | 62 kg (137 lb) | 83 kg (183 lb) |
Is BMI Accurate?
BMI can be useful for screening, but it uses only height and weight. It does not directly measure body fat, muscle mass, bone mass, or fat distribution.
For example, someone with substantial muscle mass may have a higher BMI without having the same body-fat level as another person with that BMI. A healthcare professional can help interpret results in the context of individual circumstances.
BMI for Men and Women
The standard adult BMI formula uses height and weight and does not require sex as an input. The commonly used adult screening ranges are the same for men and women, although BMI does not capture every difference in body composition.
BMI for Children and Teenagers
Adult BMI categories should not be used to interpret results for children and teenagers. BMI in younger people is assessed using age- and sex-specific growth references because body composition changes during growth. This calculator is designed for adult screening.
Using BMI With Other Health Calculators
BMI describes the relationship between height and weight, but it does not estimate every aspect of health or fitness. Use the Calorie Calculator to estimate daily calorie needs, the BMR Calculator to estimate energy used at rest, and the TDEE Calculator to estimate total daily energy expenditure.
For additional context, explore the Body Fat Calculator for a body-composition estimate, the Water Intake Calculator for a hydration estimate, or the Height Comparison Calculator to compare heights.
BMI Calculator Limitations
This calculator estimates BMI from the measurements entered. It does not diagnose disease, determine body-fat percentage, or establish an individualized healthy weight. Results may be less informative when height and weight do not reflect body composition well.
Frequently Asked Questions
What is a healthy BMI?
For adults, a BMI from 18.5 to 24.9 is commonly classified as the healthy-weight screening range. BMI should still be interpreted in context.
How is BMI calculated?
For metric measurements, divide weight in kilograms by height in meters squared. For US measurements, divide weight in pounds by height in inches squared and multiply by 703.
Can I calculate BMI using pounds and feet?
Yes. Select US Units, enter height in feet and inches, and enter weight in pounds.
Does BMI measure body fat?
No. BMI uses height and weight and does not directly measure body fat. Muscle mass and other factors can affect how BMI relates to body composition.
What is the ideal BMI?
There is no single BMI value that is ideal for everyone. For adults, 18.5 to 24.9 is commonly classified as the healthy-weight screening range, but individual circumstances matter.
Is this BMI calculator suitable for children?
No. This calculator uses standard adult BMI categories. BMI for children and teenagers is interpreted using age- and sex-specific growth references.