BMI calculator with WHO and Asian cut-offs

Written byDr. Pooja Sahu

Last Updated Nov 2, 2026

Adult BMI categories under both standards

Body mass index (BMI) is your weight in kilograms divided by the square of your height in meters. For adults 20 and older, a BMI of 18.5 to just under 25 counts as a healthy weight on the CDC adult scale, while the lower Asian scale ends the healthy range at 22.9.

The same table applies to women and men. The two scales agree on underweight and part ways where overweight begins.

Source: WHO and CDC column from the CDC adult BMI categories; Asian column from NICE guideline NG246, which sets overweight at 23 to 27.4 and obesity at 27.5 or more, then lowers obesity classes 2 and 3 by 2.5.

Take someone who is 5 feet 4 inches tall and weighs 150 pounds. Their BMI is 25.7, which is overweight on both scales. For that height, the healthy weight runs from 108 to 145 pounds under CDC cut-offs and from 108 to 133 pounds under the Asian ones.

Why Asian adults get lower cut-offs

In different Asian populations, the BMI at which the risk of type 2 diabetes and cardiovascular disease starts to rise falls between 22 and 25, below the standard overweight line of 25. A WHO expert consultation published in The Lancet in 2004 reached that finding after reviewing evidence that BMI, body fat and health risk relate differently in Asian and European populations. The panel kept 25 and 30 as the international lines for comparing countries and added public health action points at 23, 27.5, 32.5 and 37.5.

The BMI linked to high risk also varied, from 26 to 31, so no single Asian cut-off fits every group. That spread is why the calculator shows both scales side by side.

In the UK, the same lower lines are applied to adults of South Asian, Chinese, other Asian, Middle Eastern, Black African and African-Caribbean background. These groups tend to store fat around the middle and develop cardiometabolic problems, such as high blood pressure and type 2 diabetes, at a lower BMI (NICE NG246). The calculator’s background menu uses the same grouping.

Type 2 diabetes is where the lower line matters most in practice, and prediabetes statistics for US adults give the national picture.

4’10” to 6’4″: weight at each BMI cut-off

Each row shows the weight that matches a cut-off at one height, so the only number you need is your own height. Reading across shows where the Asian line at 23 and the CDC line at 25 fall for you.

Source: weights calculated as BMI × height squared from the CDC and NICE cut-offs, rounded to the nearest pound and 0.1 kg.

Two readings show when the scales agree and when they split. At 5 feet 4 inches, 140 pounds works out to 24.0: healthy by CDC standards, overweight by Asian ones. At 5 feet 9 inches, 68 kg (150 pounds) comes to 22.1, inside the healthy range on both.

Is your waist telling a different story?

Adults with a BMI under 35 are advised to keep their waist to less than half their height. In NICE NG246, a waist-to-height ratio of 0.5 to 0.59 marks increased central fat and 0.6 or more marks high central fat. These bands apply to women and men of every ethnic background, including adults with high muscle mass, a group BMI often misreads.

A 5-foot-9 man with a 32-inch waist has a ratio of 0.46 (32 ÷ 69), below the 0.5 line.

To measure your waist the way the guideline describes:

1. Find the bottom of your ribs and the top of your hip bones.
2. Wrap the tape midway between them, usually just above the belly button.
3. Breathe out normally, then read the tape.

Use the same units for waist and height, then divide the first by the second. The calculator does this for you and also compares your waist size with US and Asian waist cut-offs.

Waist checks now sit beside BMI in newer obesity criteria. Under criteria published in January 2025 by a Lancet Diabetes & Endocrinology commission, BMI screens for possible obesity, and extra body fat is confirmed with at least one waist-based measure or a direct body fat measurement such as a DXA scan. The same report separates preclinical obesity, where extra fat has not yet changed how organs work, from clinical obesity, where it has started to affect organ function or daily activities.

Muscle, age and other times BMI misleads

Two adults can share a BMI of 27 for opposite reasons. One lifts weights several times a week and carries extra muscle; the other has lost muscle over the years and gained fat around the middle. BMI reads them the same way because it only uses height and weight.

NICE NG246 asks clinicians to read BMI with caution in adults with high muscle mass and in people 65 and older, and to allow for the possibility that a slightly higher BMI is protective later in life. If you carry a lot of muscle, your waist ratio or an estimate of your body fat percentage adds what BMI leaves out.

Note: Adult categories start at age 20. For ages 2 to 19, BMI is read as a percentile for age and sex on the CDC child and teen scale, and pregnancy weight-gain targets are based on your BMI before pregnancy, the number the pregnancy weight gain calculator asks for.

The calculator follows the same rules. Enter an age under 20 and it hides the adult categories; enter 65 or older and it adds the age caution.

Bring your BMI and waist to your next checkup

Write down three numbers before your next visit: your BMI, your waist size and your waist ratio. Your BMI decides whether US screening rules call for a blood sugar test, and the waist numbers add context.

The US Preventive Services Task Force recommends screening adults aged 35 to 70 who have overweight or obesity for prediabetes and type 2 diabetes, and suggests clinicians consider screening Asian American adults at a lower BMI of 23 or above (USPSTF 2021 recommendation). The screening tests are a fasting glucose, an A1C or an oral glucose tolerance test, and when A1C screening usually starts covers timing in more detail.

Underweight (BMI below 18.5), or weight loss you did not plan, is also worth raising at the same visit.

Questions to bring:

• Based on my BMI and waist, am I due for an A1C or fasting glucose test?
• Should my healthy weight range use the Asian cut-offs?
• Has my waist-to-height ratio changed since my last visit?

The NICE waist bands apply only while BMI stays below 35.

How this was made

About this content

How this article was put together: researched from recognised health sources, drafted with the help of AI tools, and edited by hand, with sources linked throughout.

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Dr. Pooja Sahu

Researched and written from recognised health sources

Dr. Pooja Sahu, MBBS, is a medical reviewer for MyMedicineAdvisor. She is a clinical physician whose experience includes serving as a Junior Resident in Nephrology at Dr. Ram…

Content on My Medicine Advisor is researched from recognised sources, drafted with AI assistance, and edited by hand, with sources linked so you can check them. Articles medically reviewed by Dr. Pooja Sahu, MBBS, show her name and the review date. This is general health education, not medical advice.