What is a healthy weight for my height?

The calculator shows the weights that give a BMI of 18.5 and 24.9 at your height (22.9 at the top end if you choose the Asian cut-offs), and how many kg or lb you would need to lose or gain to reach that range.

Is BMI a complete measure of my health?

No — BMI doesn't distinguish between muscle and fat, so it can be misleading for very muscular individuals or older adults with reduced muscle mass. It's a useful general screening number, not a complete picture of health on its own.

How is BMI calculated on this page?

Weight in kilograms is divided by the square of height in meters. Imperial entries are converted first, using 2.54 cm per inch and 0.45359237 kg per pound. The answer is displayed to one decimal place and recalculated on every keystroke.

What are the category cut-offs?

Under 18.5 is Underweight, 18.5 up to but not including 25 is Normal, 25 up to but not including 30 is Overweight, and 30 or more is Obese. These are the usual adult bands, and the tool applies them to every entry.

Why does it say my height or weight is out of range?

Heights from 100 to 250 cm and weights from 30 to 300 kg are accepted, or the same span in feet, inches and pounds. Anything outside shows a message and no result. If you type a height like 1.7, the message asks for centimeters.

Where does the healthy range line come from?

It shows the weights that produce BMI 18.5 and BMI 24.9 at your height, found by multiplying each value by your height in meters squared. It is the main formula run backwards, so it changes only when your height changes.

Does BMI work for athletes or older adults?

It can mislead. The formula cannot tell muscle from fat, so a muscular person may land in Overweight, and an older adult who has lost muscle may land in Normal. Treat the number as a rough screen, not a verdict.

What is a healthy BMI?

For adults, 18.5 up to 24.9 is the usual healthy range. Under 18.5 is underweight, 25 to 29.9 is overweight and 30 or more is obese. With the Asian cut-offs ticked, the healthy range ends at 22.9 and obese starts at 27.5.

Is BMI different for Asian adults?

Yes, the lines are lower. Tick the Asian cut-offs box and the page moves overweight to 23 and obese to 27.5, then recalculates your category and the weight you would need to reach the healthy range.

Can children and teenagers use it?

No. Adult categories do not apply under 20. If you enter an age under 20 the page hides the category and explains that, for ages 2 to 19, BMI is read as a percentile for age and sex on the CDC growth charts. Ask a doctor about a child's weight.

What are obesity classes 1, 2 and 3?

They are the WHO bands for adults: class 1 is a BMI of 30 to 34.9, class 2 is 35 to 39.9 and class 3 is 40 or more. The table under your result shows all eight WHO classes and marks the one you are in.

What is the waist-to-height ratio?

Your waist divided by your height. Enter an optional waist measurement and the page shows the ratio and compares it with the common guideline of keeping your waist under half your height.

Who should not rely on BMI?

Children and teenagers, pregnant women, very muscular people and older adults who have lost muscle. BMI is a screening number, not a diagnosis, so talk to a doctor about your own health.

No. Height and weight stay in your browser and are never stored or uploaded.

Home/Health Calculators/BMI Calculator

BMI Calculator — Body Mass Index and Healthy Weight Range

Calculate your Body Mass Index (BMI)

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Weight (kg)

Height (cm)

Quick reference: 5'0" ≈ 152 cm · 5'4" ≈ 163 cm · 5'7" ≈ 170 cm · 5'8" ≈ 173 cm · 5'11" ≈ 180 cm · 6'2" ≈ 188 cm

Age (optional)

Sex (optional)

Waist (optional) (cm)

Use Asian BMI cut-offs (WHO: 23 and 27.5)

Your BMI

24.2

Normal

Healthy range for your height: 53.5 kg to 72.0 kg

BMI is a screening number, not a diagnosis. It does not apply to children or teenagers, and it can mislead for very muscular people, older adults and during pregnancy. Talk to a doctor about your health.

BMI Prime (BMI / 25)

0.97

1.00 is the top of the normal range

Ponderal Index (kg/m3)

14.2

Weight against height cubed

WHO adult BMI classes

WHO adult BMI classification with your class marked
WHO class	BMI (kg/m2)
Severe thinness	below 16
Moderate thinness	16 to 16.99
Mild thinness	17 to 18.49
Normal range (you)	18.5 to 24.99
Pre-obese (overweight)	25 to 29.99
Obese class I	30 to 34.99
Obese class II	35 to 39.99
Obese class III	40 and above

You are in: Normal range. Source: WHO adult BMI classification (WHO Technical Report Series 894, 2000). The Asian cut-offs option above changes the main category but not this table.

Target weight

Target BMI

A BMI of 24.9 at your height is 72.0 kg, which is gain 2.0 kg.

Formula and worked example

1. Height in metres
height in cm / 100
Using cm = 170
Result: 1.7
2. BMI
weight in kg / (height in m)^2
Using weight = 70.0 kg; height = 1.7 m
Result: 24.2
3. BMI Prime
BMI / 25
Using BMI = 24.2
Result: 0.97
4. Ponderal Index
weight in kg / (height in m)^3
Using weight = 70.0 kg; height = 1.7 m
Result: 14.2 kg/m3
5. WHO class
the WHO adult BMI table row that contains the BMI
Using BMI = 24.2
Result: Normal range (18.5 to 24.99)

Reading results never uses a trial use. Copying, saving or printing uses 1 per visit.

About BMI Calculator

Calculates Body Mass Index (BMI) from your height and weight — one general, widely-used (though imperfect) health screening measure. Accepts either metric (kg/cm) or imperial (lb/ft+in) units. For daily calorie needs specifically, use the separate Calorie Calculator tool.

Watch: BMI Calculator in Action

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What is a healthy weight for my height?: The calculator shows the weights that give a BMI of 18.5 and 24.9 at your height (22.9 at the top end if you choose the Asian cut-offs), and how many kg or lb you would need to lose or gain to reach that range.
Is BMI a complete measure of my health?: No — BMI doesn't distinguish between muscle and fat, so it can be misleading for very muscular individuals or older adults with reduced muscle mass. It's a useful general screening number, not a complete picture of health on its own.
How is BMI calculated on this page?: Weight in kilograms is divided by the square of height in meters. Imperial entries are converted first, using 2.54 cm per inch and 0.45359237 kg per pound. The answer is displayed to one decimal place and recalculated on every keystroke.
What are the category cut-offs?: Under 18.5 is Underweight, 18.5 up to but not including 25 is Normal, 25 up to but not including 30 is Overweight, and 30 or more is Obese. These are the usual adult bands, and the tool applies them to every entry.
Why does it say my height or weight is out of range?: Heights from 100 to 250 cm and weights from 30 to 300 kg are accepted, or the same span in feet, inches and pounds. Anything outside shows a message and no result. If you type a height like 1.7, the message asks for centimeters.
Where does the healthy range line come from?: It shows the weights that produce BMI 18.5 and BMI 24.9 at your height, found by multiplying each value by your height in meters squared. It is the main formula run backwards, so it changes only when your height changes.
Does BMI work for athletes or older adults?: It can mislead. The formula cannot tell muscle from fat, so a muscular person may land in Overweight, and an older adult who has lost muscle may land in Normal. Treat the number as a rough screen, not a verdict.
What is a healthy BMI?: For adults, 18.5 up to 24.9 is the usual healthy range. Under 18.5 is underweight, 25 to 29.9 is overweight and 30 or more is obese. With the Asian cut-offs ticked, the healthy range ends at 22.9 and obese starts at 27.5.
Is BMI different for Asian adults?: Yes, the lines are lower. Tick the Asian cut-offs box and the page moves overweight to 23 and obese to 27.5, then recalculates your category and the weight you would need to reach the healthy range.
Can children and teenagers use it?: No. Adult categories do not apply under 20. If you enter an age under 20 the page hides the category and explains that, for ages 2 to 19, BMI is read as a percentile for age and sex on the CDC growth charts. Ask a doctor about a child's weight.
What are obesity classes 1, 2 and 3?: They are the WHO bands for adults: class 1 is a BMI of 30 to 34.9, class 2 is 35 to 39.9 and class 3 is 40 or more. The table under your result shows all eight WHO classes and marks the one you are in.
What is the waist-to-height ratio?: Your waist divided by your height. Enter an optional waist measurement and the page shows the ratio and compares it with the common guideline of keeping your waist under half your height.
Who should not rely on BMI?: Children and teenagers, pregnant women, very muscular people and older adults who have lost muscle. BMI is a screening number, not a diagnosis, so talk to a doctor about your own health.
Is my data saved?: No. Height and weight stay in your browser and are never stored or uploaded.

How to use BMI Calculator

Choose a unit system with the two buttons at the top: Metric (kg / cm) or Imperial (lb / ft-in). Enter your weight in the first box. For height, metric mode takes centimeters in one box, while imperial mode gives separate feet and inches boxes. The form opens with 70 kg and 170 cm so a result is visible immediately, and the result card updates as you type.

The card shows your BMI to one decimal place, a category label (Underweight, Normal, Overweight or Obese) and a line giving the weight range that falls between BMI 18.5 and 24.9 at your height. Switching between metric and imperial converts the numbers already entered instead of clearing them. If a value is out of range, a red message under the box explains what is expected.

When to use it

Useful for a quick, private check of where a height and weight pair sits on the standard adult scale, for example before a routine appointment, when a form asks for your BMI, or when you are curious what a given weight change would mean. The range line shows what BMI 18.5 to 24.9 looks like in kilograms or pounds at your height.

When not to use it

Do not rely on it for children and teenagers, whose BMI is judged against age and sex charts, or during pregnancy. It also misleads for people with a lot of muscle, and says nothing about where body fat sits, fitness or blood results. For decisions about weight, ask a doctor or dietitian, who can use measurements this calculator cannot.

Tips for best results

Enter height in centimeters, not meters: typing 1.70 in the centimeter box triggers a hint telling you to enter 170. Weigh yourself at a consistent time, such as the morning, if you compare readings over several weeks. To set a target, read the healthy range line first, since it already converts the BMI band into kilograms or pounds for your own height.

Limitations

The formula is weight in kilograms divided by height in meters squared, with fixed cut-offs at 18.5, 25 and 30. The tool does not adjust for age, sex, ethnicity or muscle mass. It accepts weights from 30 to 300 kg and heights from 100 to 250 cm. BMI is a rough screening number, and this result is general information and not medical or professional advice.

Privacy

Your height and weight are used only for the calculation, which runs in your browser as you type. They are not stored, tied to an account or sent anywhere, so closing the tab erases them. The page does report a small usage count naming the tool, but it carries none of the numbers you entered.