What is a healthy BMI on the chart?

18.5 to 24.9 for adults. That band is where population studies show the lowest all-cause mortality risk, though the curve is shallow across most of it.

What BMI is classed as obese?

30.0 and above. It is subdivided into class I (30.0-34.9), class II (35.0-39.9) and class III (40.0 and above), which clinicians use when deciding on treatment intensity.

Is the BMI chart different for men and women?

No. The adult chart uses identical categories for both. Children and teenagers are the exception - they need age-and-sex percentile charts, because healthy BMI changes throughout growth.

Why do some BMI charts show 23 as a cut-off?

Those are the WHO Asian-specific action points. Cardiometabolic risk rises at a lower index in South Asian, Chinese and several other populations, so 23 and 27.5 are used instead of 25 and 30.

What is a BMI scale versus a BMI chart?

They are the same thing described two ways: the continuous index and the named bands it is divided into. Some printed charts also plot height against weight as a grid, which is just the equation drawn out.

BMI Chart for Adults

See the full adult BMI chart, then calculate exactly where your own height and weight fall on it.

Enter your details and your result will appear here.

What Is BMI Chart?

The adult BMI chart maps body mass index onto four named categories, from underweight through to obesity. It is the reference clinicians, insurers and public-health bodies use to describe weight-for-height at a glance.

Rather than reading your value off a printed grid, enter your height and weight below and the calculator places you on the scale directly, then shows the weight range that corresponds to each category at your height.

Understanding Your BMI Chart Result

The chart is built from a single number. BMI below 18.5 is underweight, 18.5 to 24.9 is the healthy range, 25.0 to 29.9 is overweight, 30.0 to 34.9 is obesity class I, 35.0 to 39.9 is class II and 40.0 or above is class III. Below 16 is sometimes labelled severe thinness.

These are population thresholds, chosen because the risk of conditions such as type 2 diabetes and cardiovascular disease starts to climb measurably around them. They are boundaries on a continuous scale, not cliffs: a BMI of 25.1 is not meaningfully different from 24.9.

How Is BMI Chart Calculated?

BMI = weight (kg) / height (m)^2

Category boundaries: under 18.5 underweight, 18.5-24.9 healthy, 25.0-29.9 overweight, 30.0 and above obesity.

How to read the BMI chart

Find your height, then read across to your weight. The band your weight falls into is your category. The calculator above does this exactly, with the added advantage of interpolating between the rows a printed chart has to round to.

What the chart is genuinely good for is seeing distance: how far a given weight sits from the edge of a band tells you far more than the label itself.

Factors that change where you land

Muscle mass pushes you up the chart without any change in body fat. Fluid retention adds a few pounds within a single day. Losing height with age moves you up the chart at a constant weight, because BMI divides by height squared.

Ancestry shifts the thresholds rather than your position: the same index carries different risk in different populations.

Using the chart sensibly

Treat a category as the start of a question, not the answer. Pair it with a waist measurement - above 35 in for women or 40 in for men flags abdominal fat that the chart cannot see - and with how your weight has moved over the past year.

If you want to know what your weight is made of rather than how much of it there is, a body-fat or lean body mass estimate is the next step.

Methodology

Every value on the chart comes from BMI = weight (kg) / height (m)^2, classified with the World Health Organization adult scale used by the NHS, the CDC and most national health bodies.

The healthy-weight range shown for your height is that same equation solved for weight at BMI 18.5 and 24.9.

Worked Example

At 5 ft 8 in (173 cm) the chart translates to roughly: under 121 lb underweight, 121-163 lb healthy, 164-196 lb overweight and 197 lb or more in the obesity range.

At 6 ft 0 in (183 cm) those same categories shift to under 136 lb, 136-183 lb, 184-220 lb and 221 lb or more. That shift is the whole point of using a chart rather than a single target weight.

Important Limitations

A chart position is a description, not a diagnosis. BMI does not measure body fat, does not know where fat is stored, and misclassifies muscular people in both directions. Asian populations reach equivalent cardiometabolic risk at lower values, which is why the WHO also publishes action points at 23 and 27.5 for those groups. Adults over 65 may do better slightly higher on the chart than the standard band suggests, and the adult chart does not apply to anyone under 18.

Frequently Asked Questions

What is a healthy BMI on the chart?: 18.5 to 24.9 for adults. That band is where population studies show the lowest all-cause mortality risk, though the curve is shallow across most of it.
What BMI is classed as obese?: 30.0 and above. It is subdivided into class I (30.0-34.9), class II (35.0-39.9) and class III (40.0 and above), which clinicians use when deciding on treatment intensity.
Is the BMI chart different for men and women?: No. The adult chart uses identical categories for both. Children and teenagers are the exception - they need age-and-sex percentile charts, because healthy BMI changes throughout growth.
Why do some BMI charts show 23 as a cut-off?: Those are the WHO Asian-specific action points. Cardiometabolic risk rises at a lower index in South Asian, Chinese and several other populations, so 23 and 27.5 are used instead of 25 and 30.
What is a BMI scale versus a BMI chart?: They are the same thing described two ways: the continuous index and the named bands it is divided into. Some printed charts also plot height against weight as a grid, which is just the equation drawn out.