# 123BMICalculator

> Free BMI calculator for adults, kids and teens, with your healthy weight range, BMI chart, Asian cut-offs, body fat, waist-to-height ratio, BMR and calories. No sign-up, nothing stored.

123BMICalculator (123bmicalculator.com) is a free website of BMI and body-measurement calculators. BMI is weight in kilograms divided by height in metres squared, reported to one decimal and classified on that one-decimal value (CDC's convention). Adults are classified by the WHO/CDC cut-offs, or by Asian cut-offs where chosen; anyone aged 2 to 19 is classified by BMI-for-age percentile on the CDC growth charts, never by adult cut-offs. Every result has a URL, works without JavaScript, and nothing the user enters is stored. There are no accounts, ads or tracking cookies. Results are screening information, not medical advice.

## BMI calculators

- [BMI Calculator](https://123bmicalculator.com/): Body mass index, its category and your healthy weight range.
- [BMI Calculator for Women](https://123bmicalculator.com/bmi-calculator-for-women): BMI with a body-fat estimate and waist check for women.
- [BMI Calculator for Men](https://123bmicalculator.com/bmi-calculator-for-men): BMI with a body-fat estimate and waist check for men.
- [BMI Calculator for Kids & Teens](https://123bmicalculator.com/bmi-calculator-for-kids): BMI-for-age percentile for ages 2 to 19 (CDC growth charts).
- [Asian BMI Calculator](https://123bmicalculator.com/asian-bmi-calculator): BMI by Asian cut-offs: WHO 2004, NICE, China, Japan, India, Korea.
- [BMI Calculator for Seniors](https://123bmicalculator.com/bmi-calculator-for-seniors): BMI after 65, with the low-BMI line for your age and a weight-loss check.

## Healthy weight

- [Healthy Weight Calculator](https://123bmicalculator.com/healthy-weight-calculator): The healthy weight range for any height, in lb or kg.
- [Ideal Weight Calculator](https://123bmicalculator.com/ideal-weight-calculator): Ideal body weight by Devine, Robinson, Miller and Hamwi.
- [Goal Weight Calculator](https://123bmicalculator.com/goal-weight-calculator): Your goal weight, goal BMI and the date you could reach it.
- [Pregnancy Weight Gain Calculator](https://123bmicalculator.com/pregnancy-weight-gain-calculator): Recommended pregnancy weight gain by week, from the IOM guidelines.

## Body shape & fat

- [Body Fat Calculator](https://123bmicalculator.com/body-fat-calculator): Body fat % from a tape measure: US Navy method, RFM and BMI.
- [Waist-to-Height Ratio Calculator](https://123bmicalculator.com/waist-to-height-ratio-calculator): Waist ÷ height: keep it under 0.5 (NICE).
- [Waist-to-Hip Ratio Calculator](https://123bmicalculator.com/waist-to-hip-ratio-calculator): Waist ÷ hips, with the WHO risk line: 0.90 men, 0.85 women.
- [Body Roundness Index Calculator](https://123bmicalculator.com/body-roundness-index-calculator): BRI from height and waist, with the 2024 risk bands.

## Calories

- [BMR Calculator](https://123bmicalculator.com/bmr-calculator): Calories burned at rest: Mifflin–St Jeor, Harris–Benedict, Katch–McArdle.
- [Calorie Calculator](https://123bmicalculator.com/calorie-calculator): Daily calories to maintain, lose or gain weight.

## Guides

- [BMI chart](https://123bmicalculator.com/bmi-chart): adult BMI table by height and weight, in pounds and kilograms, with the healthy weight range for every height from 4 ft 10 in to 6 ft 6 in.
- [How BMI is calculated](https://123bmicalculator.com/how-bmi-is-calculated): the formula, the rounding rule, every classification used on the site, the child percentile method, and where BMI falls short — with sources.
- [All calculators](https://123bmicalculator.com/calculators): every calculator and which one to use.

## Linking to a result

Every calculator accepts its inputs in the query string, so a link can open a finished result. unit=us takes ft, in and weight in pounds (lb); unit=metric takes cm and weight in kg. Tape measurements (waist, hip, neck) are in inches or cm to match. sex is male or female.

- BMI Calculator: https://123bmicalculator.com/?unit=us&ft=5&in=9&weight=165
- BMI Calculator for Women: https://123bmicalculator.com/bmi-calculator-for-women?unit=us&ft=5&in=4&weight=150&age=45&waist=33
- BMI Calculator for Men: https://123bmicalculator.com/bmi-calculator-for-men?unit=us&ft=5&in=10&weight=190&age=40&waist=38
- BMI Calculator for Kids & Teens: https://123bmicalculator.com/bmi-calculator-for-kids?unit=us&sex=female&age_y=10&age_m=0&ft=4&in=7&weight=75
- Asian BMI Calculator: https://123bmicalculator.com/asian-bmi-calculator?unit=metric&cm=168&weight=68&std=asia
- BMI Calculator for Seniors: https://123bmicalculator.com/bmi-calculator-for-seniors?unit=us&age=74&ft=5&in=6&weight=140&before=150&bg=other
- Healthy Weight Calculator: https://123bmicalculator.com/healthy-weight-calculator?unit=us&ft=5&in=6&std=who
- Ideal Weight Calculator: https://123bmicalculator.com/ideal-weight-calculator?unit=us&sex=female&ft=5&in=4
- Goal Weight Calculator: https://123bmicalculator.com/goal-weight-calculator?unit=us&ft=5&in=9&weight=190&goal=165&pace=1
- Pregnancy Weight Gain Calculator: https://123bmicalculator.com/pregnancy-weight-gain-calculator?unit=us&ft=5&in=5&before=140&week=20&now=152&babies=one
- Body Fat Calculator: https://123bmicalculator.com/body-fat-calculator?unit=us&sex=male&age=40&ft=5&in=10&weight=180&neck=15.5&waist=34
- Waist-to-Height Ratio Calculator: https://123bmicalculator.com/waist-to-height-ratio-calculator?unit=us&ft=5&in=9&waist=36&sex=male
- Waist-to-Hip Ratio Calculator: https://123bmicalculator.com/waist-to-hip-ratio-calculator?unit=us&sex=female&waist=32&hip=40
- Body Roundness Index Calculator: https://123bmicalculator.com/body-roundness-index-calculator?unit=us&ft=5&in=9&waist=36
- BMR Calculator: https://123bmicalculator.com/bmr-calculator?unit=us&sex=female&age=35&ft=5&in=5&weight=150
- Calorie Calculator: https://123bmicalculator.com/calorie-calculator?unit=us&sex=male&age=40&ft=5&in=10&weight=180&activity=1.55

## Key facts

- Formula: BMI = kg / m². In US units, BMI = 703 × lb / in². Example: 5 ft 9 in and 165 lb is BMI 24.4.
- Adult categories (WHO, CDC): underweight below 18.5; healthy weight 18.5–24.9; overweight 25–29.9; obesity class 1 30–34.9, class 2 35–39.9, class 3 40 or more.
- Healthy weight at 5 ft 9 in: 125–168 lb (CDC's own example). At 175 cm: 56.6–76.4 kg.
- Asian cut-offs (WHO expert consultation 2004; NICE): overweight from 23, obesity from 27.5. China: overweight 24, obesity 28. Japan: obesity from 25.
- Children and teens (2–19): CDC BMI-for-age percentiles — underweight below the 5th, healthy 5th to below 85th, overweight 85th to below 95th, obesity 95th or above; severe obesity from 120% of the 95th percentile (AAP 2023). Above the 95th percentile the CDC 2022 extended method is used.
- Waist-to-height ratio: keep your waist to less than half your height (ratio below 0.5), as NICE advises.
- Since 2025 (Lancet Diabetes & Endocrinology Commission), BMI alone is not considered enough to diagnose obesity; it should be confirmed with a waist measure or body-fat measurement, except above BMI 40.
- Price: free. Last updated: 2026-10-31