Adult Body Mass Index (BMI) Calculator and Table

Author: Ian C. Langtree - Writer/Editor for Disabled World (DW)
Published: 22 Dec 2017 - Updated: 19 Aug 2026
Publication Type: Charts, Graphs, Tables

Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content

Synopsis

A Body Mass Index (BMI) calculator is a valuable tool for assessing an individual's health status related to their weight and height. It provides a quick and easy way to determine if a person falls within a healthy weight range, is underweight, overweight, or obese. When combined with waist circumference measurements, BMI can help identify potential health risks associated with excess body fat, such as an increased risk for type 2 diabetes, cardiovascular disease, and hypertension. This information can be particularly useful for healthcare professionals and individuals alike in evaluating overall health, setting weight management goals, and monitoring progress over time. However, it's important to note that BMI is just one factor in assessing overall health and should be considered alongside other health indicators and individual circumstances.

At a Glance

• 1 - Children aged 1 to 20 need a separate calculator, as adult cutoffs do not fit growing bodies.
• 2 - The World Health Organization splits obesity into three classes: 30 to 34.9, 35 to 39.9, and 40 upwards.
• 3 - U.S. survey data from 2011 to 2014 placed the median BMI at 27.7 for both men and women aged 20 and over.
• 4 - The imperial formula divides weight in pounds by height in inches squared, then multiplies the result by 703.

Topic Definition

Body Mass Index (BMI)

Body Mass Index, commonly shortened to BMI, is a simple numerical value calculated from a person's weight and height that estimates whether their body weight sits in a healthy range for their stature. The figure is found by dividing weight by the square of height, then applying a conversion factor depending on whether you work in imperial or metric units, and the result places an adult into categories ranging from underweight through normal, overweight, and three classes of obesity. Doctors and individuals rely on it as a quick, low cost screening step because it needs only a scale and a measuring tape, yet it does not directly measure body fat and cannot tell muscle from fat. For that reason BMI works best as a starting point that is read alongside other markers such as waist circumference, blood pressure, blood sugar, cholesterol, and family history rather than as a standalone verdict on someone's health.

Overview

Understanding Your Weight to Height Ratio and What It Reveals About Your Health

The body mass index (BMI) is a number derived from a formula, used to compare and analyze the health effects of weight on people of all ages and heights. Use our instant online body mass index calculator to find your current BMI measurement and learn how to measure your waist circumference.

Your body mass index measurement combined with your Waist Circumference measurement can be used to determine obesity and the increased risk for various diseases. A high waist circumference is often associated with an increased risk for type 2 diabetes, cardiovascular disease, dyslipidemia and hypertension when your BMI is calculated between 25 and 34.9.

NOTE: For children aged 1 to 20 use our Body Mass Index Calculator for Children to calculate a child's BMI.

How to Measure Waist Circumference

Waist Circumference measurement is handy for people whose BMI indicates they maybe normal or overweight. EG. an athlete with an increased muscle mass may have a BMI greater than 25 - making them overweight on the BMI scale, however a Waist Circumference measurement would indicate that they are in fact not overweight. Men with a waist circumference more than 102 cm (40 in) and women with a waist circumference more than 88 cm (35 in) are at increased risk of developing health problems - Male and Female Waist to Hip Ratio Calculator

Find your upper hip bone, the waist is usually measured at one inch above the naval, place a measuring tape around the abdomen, be sure the tape is horizontal, the tape measure should be firm but should not compress the skin. Changes in your waist circumference over time can indicate an increase or decrease in your abdominal fat, an increase in abdominal fat is associated with an greater risk of developing heart disease. Physical activity and good nutrition are key factors in a healthy lifestyle.

Remember, BMI is only one piece of a person's health profile and just one of the many factors related to developing a serious disease. There are other factors that are important when assessing your risk for chronic disease including:

Adult BMI Chart

To read the Adults BMI chart, or table, find your height in the left-hand column labeled Height. Then move across to your weight (in pounds). The number at the top of the column is the correct BMI measurement for that height and weight. To keep the page mobile friendly, the chart consists of 4 progressive tables - so if your numbers don't match the first table move down to the next one.

(Pounds have been rounded off)*. See further down the page for a printable BMI chart for adults.

BMI for Males - Percentiles by Age: U.S. 2011-2014

BMI for Females - Percentiles by Age: U.S. 2011-2014

English and Metric Formula for Calculating BMI

Imperial BMI Formula

Body Mass Index is calculated using pounds and inches with this equation:

BMI = (Weight in Pounds (Height in inches) x (Height in inches) ) x 703

For example, a person who weighs 220 pounds and is 6 feet 3 inches tall has a BMI of 27.5

(220 lbs. (75 inches) x (75 inches) ) x 703 = 27.5

Metric BMI Formula

BMI = Weight in Kilograms (Height in Meters) x (Height in Meters)

BMI = (Weight in Kilograms (Height in centimeters) x (Height in centimeters) ) x 10,000

For example, a person who weighs 99.79 Kilograms and is 1.905 Meters (190.50 centimeters) tall has a BMI of 27.5.

99.79 Kg (1.905 m) x (1.905 m) = 27.5

Printable version of a BMI chart for adults.

*BMI data courtesy of National Institute of Health (NIH) - National Heart, Lung, and Blood Institute (NHLBI).

Frequently Asked Questions

Who created the body mass index formula?

The Belgian mathematician Adolphe Quetelet developed the calculation in the 1830s while studying average human physical measurements, and it was originally known as the Quetelet Index. The name body mass index came much later, popularized in 1972 by the American physiologist Ancel Keys.

Are there different BMI cutoffs for people of Asian descent?

Yes. The World Health Organization and several national agencies recommend lower action points for many Asian populations, often treating roughly 23 as overweight and 27.5 as obese, because diabetes and heart risk can appear at lower body weights.

How is BMI estimated for someone who cannot stand for a height measurement?

Clinicians use proxy measures such as arm span, half arm span, knee height, or ulna length and convert them to estimated stature with published equations. For people with limb loss, body weight is adjusted upward by the share of mass the missing limb would normally contribute.

What health risks come with a BMI below 18.5?

Being underweight is associated with lower bone density, anemia, weakened immunity, fertility difficulties, and slower recovery from illness or surgery. A persistently low reading can also point to thyroid disease, malabsorption, or an eating disorder that needs medical review.

Do doctors and insurers use BMI thresholds to approve treatments?

BMI frequently appears in eligibility rules for bariatric surgery, prescription weight management drugs, and some fertility or joint replacement programs. Those rules differ by country and insurer, so an identical number can produce different decisions in different health systems.

What methods measure body fat more directly than BMI?

Common options include skinfold calipers, bioelectrical impedance scales, air displacement plethysmography, underwater weighing, and DEXA scanning, which is usually treated as the practical reference standard. Cost, availability, and accuracy vary widely, and cheaper home devices are easily skewed by hydration.

Are there alternatives to BMI that use the same simple measurements?

Yes. BMI Prime expresses the result as a ratio of the upper healthy limit, the ponderal index cubes height instead of squaring it, and waist to height ratio compares abdominal girth with stature. All of them still need only a scale and a tape measure.

How much can BMI fluctuate from day to day?

Shifts in hydration, food in the digestive tract, glycogen stores, and hormonal cycles can move scale weight by several pounds in a single day, which can nudge BMI by around half a point. Weighing at the same time of day under similar conditions gives a far more trustworthy trend.

Insights, Analysis, and Developments

Editorial Note: While BMI remains the most accessible screening tool for weight-related health risks - requiring nothing more than a tape measure and a bathroom scale - its limitations deserve acknowledgment. The formula treats a powerlifter and a sedentary office worker with identical height and weight as health equals, ignoring the fundamental difference between muscle and fat. More problematic still, the thresholds were derived primarily from studies of European populations, making them potentially misleading for individuals of Asian, Polynesian, or African descent, whose body composition and disease risk profiles often differ markedly. For people with disabilities, particularly those affecting mobility or muscle mass, BMI becomes even less reliable as a health indicator. The message here isn't to abandon BMI entirely - it's simply too useful as a first approximation - but rather to recognize it as the starting point of a conversation, not the conclusion. Your doctor's assessment should weigh BMI alongside waist circumference, blood work, family history, and perhaps most importantly, how you actually feel in your own body. Numbers tell part of the story; they shouldn't be mistaken for the whole narrative.

Author Credentials: Ian is the founder and Editor-in-Chief of Disabled World, a leading resource for news and information on disability issues. With a global perspective shaped by years of travel and lived experience, Ian is a committed proponent of the Social Model of Disability, a transformative framework developed by disabled activists in the 1970s that emphasizes dismantling societal barriers rather than focusing solely on individual impairments. His work reflects a deep commitment to disability rights, accessibility, and social inclusion. To learn more about Ian's background, expertise, and accomplishments, visit his full biography.