--- title: "BMI Calculator (Metric & Imperial) — Adult BMI | GLPMate" url: https://glpmate.me/tools/bmi-calculator language: en description: "Free adult BMI calculator in metric or imperial: your WHO/CDC category and healthy-weight range, plus what BMI can and can't tell you on a GLP-1." updated: 2026-10-14 --- Free tool · no signup # BMI calculator Enter your height and weight to see your body mass index, the adult category it falls in and the healthy-weight range for your height. Everything is calculated in your browser. **Your BMI, updated at every weigh-in** GLPMate tracks weight and BMI over time — log a weigh-in or just tell the assistant your weight. [ Download on the **App Store** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-bmi-calculator&adj_redirect_android=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_macos=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_windows=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235) [ GET IT ON **Google Play** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-bmi-calculator&adj_redirect_ios=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_macos=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_windows=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate) Quick answer BMI is weight in kilograms divided by height in metres squared. For adults, a BMI under 18.5 is underweight, 18.5–24.9 is a healthy weight, 25–29.9 is overweight and 30 or more is obesity (WHO and CDC). It is a screening number, not a diagnosis: it can't tell muscle from fat, and it isn't used for children or during pregnancy. **BMI and GLP-1 prescribing:** weight-management medicines such as Wegovy and Zepbound are approved for adults with obesity, or with overweight plus at least one weight-related condition such as high blood pressure or type 2 diabetes. In the trials behind them, that meant a BMI of 30 or more, or 27 or more with a condition. Only a clinician can decide whether a medicine is right for you. [Check the full criteria →](/tools/glp-1-eligibility-checker) ## How BMI is calculated BMI = weight (kg) ÷ height (m)². With pounds and inches the formula is 703 × weight (lb) ÷ height (in)²; this calculator converts to metric first, so both give the same answer. The adult categories below are the ones used by the WHO and the US CDC. Category | BMI (kg/m²) Underweight | < 18.5 Healthy weight | 18.5–24.9 Overweight | 25.0–29.9 Obesity (class 1) | 30.0–34.9 Obesity (class 2) | 35.0–39.9 Obesity (class 3) | ≥ 40.0 ### What BMI can't tell you BMI doesn't tell muscle from fat, so a very muscular person can score as overweight while carrying little fat, and an older adult can score as a healthy weight with little muscle. It also says nothing about where fat sits — waist size adds that information. ### Who it isn't for These categories are for adults. Children and teenagers are assessed with BMI-for-age percentiles instead, and BMI isn't used to judge weight during pregnancy. ### Ethnicity and cut-offs Health risks start at a lower BMI in some populations. A WHO expert consultation proposed lower action points for Asian populations (such as 23 and 27.5), and some national guidelines use them. Ask your clinician which cut-offs apply to you. ## Related free tools [ **Eligibility checker** BMI plus the clinical criteria for weight-management GLP-1s. Open tool → ](/tools/glp-1-eligibility-checker)[ **Weight-loss percentage** How much of your starting weight you've lost. Open tool → ](/tools/weight-loss-percentage-calculator)[ **Weight & BMI tracker** Log your weight in the app and follow the trend, not the day. Learn more → ](/glp-1-weight-tracker) This calculator is for general education only. It is not medical advice or a diagnosis, and it doesn't decide whether any medicine is right for you — that is a conversation with your clinician. ## Sources 1. [CDC adult BMI categories (the same cut-offs the WHO uses)](https://www.cdc.gov/bmi/adult-calculator/bmi-categories.html) — underweight, healthy weight, overweight and obesity classes 1–3 2. [WHO expert consultation on BMI in Asian populations (The Lancet, 2004)](https://doi.org/10.1016/S0140-6736(03)15268-3) — lower public-health action points such as 23 and 27.5 3. FDA prescribing information for Wegovy and Zepbound ([Wegovy](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=215256), [Zepbound](https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=217806)) — weight-management indications: obesity, or overweight with at least one weight-related condition Last updated: 2026-10-14 FAQ ## BMI questions ### What is a healthy BMI for adults? For adults, the WHO and CDC class a BMI of 18.5 to 24.9 as a healthy weight. Below 18.5 is underweight, 25 to 29.9 is overweight and 30 or more is obesity, which is split into class 1 (30–34.9), class 2 (35–39.9) and class 3 (40 or more). ### What BMI do you need for Wegovy or Zepbound? Their labels cover adults with obesity, or with overweight plus at least one weight-related condition. In the trials behind them, that meant a BMI of 30 or more, or 27 or more with a condition such as high blood pressure, type 2 diabetes or high cholesterol. Insurance rules are often stricter, and only a clinician can prescribe. ### Is BMI accurate if I am muscular? Not very. BMI uses only height and weight, so it can label a muscular person as overweight. Waist circumference or a body-composition measurement gives a fuller picture, and your clinician can help you interpret them. ### Does BMI work for Asian adults, children or pregnancy? Health risks start at a lower BMI in Asian populations, so some guidelines use lower cut-offs. Children and teenagers are assessed with BMI-for-age percentiles instead of the adult categories, and BMI isn't used to judge weight during pregnancy. ## Track the trend, not one number. Weight, BMI and measurements in the GLPMate app. iOS & Android. [ Download on the **App Store** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-bmi-calculator&adj_redirect_android=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_macos=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235&adj_redirect_windows=https%3A%2F%2Fapps.apple.com%2Fapp%2Fid6788548235) [ GET IT ON **Google Play** ](https://glpmate.go.link?adj_t=22klhq12&adj_campaign=tools-bmi-calculator&adj_redirect_ios=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_macos=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate&adj_redirect_windows=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dapp.eleutheromania.glpmate)