Free calculator · adults · no sign-up
Enter your height to see the healthy weight range that health services use for adults. Add your weight to work out your body mass index (BMI), and your waist size for the waist-to-height ratio. Everything is calculated in your browser; nothing is sent or stored.
This tool gives general information and does not replace advice from a doctor or dietitian.
The ranges come from the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) adult categories, with the lower thresholds that NICE, in England, recommends for some ethnic groups. How the calculator works.
BMI is your weight in kilograms divided by your height in metres squared. Someone who weighs 70 kg and is 1.70 m tall has a BMI of 70 ÷ (1.70 × 1.70) = 24.2. Pounds and inches are converted first (1 inch = 2.54 cm, 1 lb = 0.4536 kg).
The healthy weight range for a height is simply the weights that give a BMI from 18.5 to 24.9: at 5 ft 4 in, 108 to 145 lb; at 5 ft 10 in, 129 to 173 lb; at 170 cm, 53.5 to 71.9 kg.
For people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, NICE uses 23 and 27.5 instead of 25 and 30. See adult BMI categories explained.
BMI is a screening measure, not a diagnosis. It does not tell muscle from fat, so it can overstate risk for very muscular people, and it should be read with care after 65 and not used in pregnancy. Waist-to-height ratio adds information about fat around the middle. Children and teenagers need age- and sex-specific percentiles instead: see BMI for children and teens.
What the numbers mean, how they are calculated, and where they stop being useful.
Healthy weight & BMIA table of healthy weight ranges for adults from 4 ft 10 in to 6 ft 6 in and 150 to 195 cm, with how the range is worked out and when it does not apply.
Healthy weight & BMIWhy health services use BMI to describe a healthy weight, what it misses, which other measures help and what affects weight beyond food and exercise.
Healthy weight & BMIKeep your waist to less than half your height: how to measure, how to calculate the ratio and what the NICE bands mean.
The weekly guidelines, strength exercises and walking, from public health advice.
Physical activity150 minutes of moderate activity a week, strength exercises on two days and less sitting: what counts, how to judge intensity and how to start.
Physical activityStrength exercises on two days a week, as the guidelines recommend: what counts, simple moves to start at home, and how to progress safely.
Physical activityA brisk 10-minute walk already counts. What brisk means, whether 10,000 steps is official, and how to make walking part of every day.
Practical guide
Walkable streets, parks within reach, a commute you can do on foot or by bike, somewhere to exercise and a bedroom quiet enough to sleep: what to look at before you choose where to live.
Read the guideThe everyday food advice that public health bodies agree on, without diets or products.
Nutrition basicsThe five food groups of the Eatwell Guide, the WHO's four principles of a healthy diet, and how to turn them into ordinary meals.
Nutrition basicsWhat counts as a portion, why potatoes do not, the limits on juice and pulses, and how 5 A Day relates to the WHO's 400 g a day.
Nutrition basicsMost adults eat about 20 g of fibre a day against a recommended 30 g. Why it matters, where it comes from and how to add more gradually.
Sleep & stressSeven or more hours for most adults: the official recommendations by age, why timing and quality matter, and signs you are running short.
Sleep & stressA regular routine, a calm hour before bed, a dark, quiet and cool room, and what to do when you cannot sleep.
Sleep & stressStress can change sleep and appetite. The coping steps the NHS and WHO recommend, the habits that backfire, and when to ask for help.