A BMI of 50 is classed as severe obesity (class 3) for most adults (NHS). For people of South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean background it is classed as severe obesity (class 3) (NICE). The healthy range is 18.5 to 24.9.
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What a BMI of 50 means
Body mass index (BMI) compares your weight with your height. A BMI of 50 means you weigh 50 kilograms for every square metre of your height. Using the NHS categories, a BMI of 50 is classed as severe obesity (class 3) for most adults.
Most adults
BMI 50 = severe obesity (class 3). NHS ranges: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30+ obesity.
South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean
BMI 50 = severe obesity (class 3). NICE uses lower cut-offs of 23 and 27.5 because health risks start at a lower BMI.
Your BMI is 25.1 points above the top of the healthy range (24.9). For comparison, the average BMI of adults in England is 27.6 (Health Survey for England 2022), and 64% of adults have a BMI of 25 or more.
Weight at a BMI of 50 for every height
Find your height to see the weight that gives a BMI of 50, in kilograms, stones and pounds. The last column shows the top of the healthy range (BMI 24.9).
| Height | Weight at BMI 50 | Stones & pounds | Pounds | Healthy limit |
|---|---|---|---|---|
| 4′10″ (147 cm) | 108.5 kg | 17 st 1 lb | 239 lb | 54.0 kg |
| 4′11″ (150 cm) | 112.3 kg | 17 st 10 lb | 248 lb | 55.9 kg |
| 5′0″ (152 cm) | 116.1 kg | 18 st 4 lb | 256 lb | 57.8 kg |
| 5′1″ (155 cm) | 120.0 kg | 18 st 13 lb | 265 lb | 59.8 kg |
| 5′2″ (157 cm) | 124.0 kg | 19 st 7 lb | 273 lb | 61.8 kg |
| 5′3″ (160 cm) | 128.0 kg | 20 st 2 lb | 282 lb | 63.8 kg |
| 5′4″ (163 cm) | 132.1 kg | 20 st 11 lb | 291 lb | 65.8 kg |
| 5′5″ (165 cm) | 136.3 kg | 21 st 6 lb | 300 lb | 67.9 kg |
| 5′6″ (168 cm) | 140.5 kg | 22 st 2 lb | 310 lb | 70.0 kg |
| 5′7″ (170 cm) | 144.8 kg | 22 st 11 lb | 319 lb | 72.1 kg |
| 5′8″ (173 cm) | 149.2 kg | 23 st 7 lb | 329 lb | 74.3 kg |
| 5′9″ (175 cm) | 153.6 kg | 24 st 3 lb | 339 lb | 76.5 kg |
| 5′10″ (178 cm) | 158.1 kg | 24 st 12 lb | 348 lb | 78.7 kg |
| 5′11″ (180 cm) | 162.6 kg | 25 st 8 lb | 358 lb | 81.0 kg |
| 6′0″ (183 cm) | 167.2 kg | 26 st 5 lb | 369 lb | 83.3 kg |
| 6′1″ (185 cm) | 171.9 kg | 27 st 1 lb | 379 lb | 85.6 kg |
| 6′2″ (188 cm) | 176.6 kg | 27 st 11 lb | 389 lb | 88.0 kg |
| 6′3″ (190 cm) | 181.5 kg | 28 st 8 lb | 400 lb | 90.4 kg |
| 6′4″ (193 cm) | 186.3 kg | 29 st 5 lb | 411 lb | 92.8 kg |
| 6′5″ (196 cm) | 191.3 kg | 30 st 2 lb | 422 lb | 95.2 kg |
| 6′6″ (198 cm) | 196.3 kg | 30 st 13 lb | 433 lb | 97.7 kg |
A BMI of 50 for women and men
The NHS uses the same BMI categories for women and men, so a BMI of 50 is severe obesity (class 3) whether you are male or female. What differs is body composition: at the same BMI, women usually carry more body fat than men, and men tend to carry more fat around the waist.
BMI 50 for a woman
A 5′4″ (163 cm) woman with a BMI of 50 weighs about 132.1 kg (20 st 11 lb). To reach a BMI of 24.9 she would need to lose about 66.3 kg (10 st 6 lb). After the menopause, fat tends to move towards the waist, so a waist check is especially useful.
BMI 50 for a man
A 5′10″ (178 cm) man with a BMI of 50 weighs about 158.1 kg (24 st 12 lb). To reach a BMI of 24.9 he would need to lose about 79.3 kg (12 st 7 lb). Very muscular men can have a high BMI without excess fat, which is why waist size matters too.
Is BMI 50 different by age? No – adult BMI categories are the same from 18 onwards. Over 65, a BMI between about 23 and 28 is not usually a concern, and losing weight without trying should always be checked by a GP. Children need a BMI centile instead.
Health risks at a BMI of 50
A BMI of 50 is in the obesity range. The NHS explains that obesity raises the risk of type 2 diabetes, coronary heart disease, stroke, some types of cancer (including breast and bowel cancer), fatty liver disease, osteoarthritis and sleep apnoea. Risks rise further at higher BMI levels and when weight is carried around the waist.
BMI cannot tell fat from muscle, so it is best used with a second measure. NICE recommends a waist-to-height ratio: keep your waist to less than half your height.
What to do next
- Set a first goal of 5% weight loss. That is about 6.6 kg for a 5′4″ woman or 7.9 kg for a 5′10″ man at this BMI.
- Aim for 0.5–1 kg (1–2 lb) a week with a daily deficit of about 600 kcal – use the calorie deficit calculator.
- Move more: build up to 150 minutes of moderate activity a week plus 2 days of strength exercise.
- Use free NHS support: the NHS Weight Loss Plan app, or ask your GP or pharmacist about local weight management services and whether you could be referred to a specialist service.
- Talk to your GP about medical options: NICE recommends weight loss medicines and surgery only at certain BMI levels and with specialist support. For example, surgery is usually considered at a BMI of 40 or more, or 35 or more with a related condition such as type 2 diabetes.
Frequently asked questions
Is a BMI of 50 good?
A BMI of 50 is classed as severe obesity (class 3) for most adults by the NHS. The healthy range is 18.5 to 24.9, so a BMI of 50 is above it.
Is a BMI of 50 obese?
For most adults, a BMI of 50 is severe obesity (class 3). For South Asian, Chinese, other Asian, Middle Eastern, Black African and African-Caribbean adults, NICE classes it as severe obesity (class 3).
How much should I weigh to have a BMI of 50?
It depends on your height. A 5′4″ (163 cm) person would weigh about 132.1 kg (20 st 11 lb), and a 5′10″ (178 cm) person about 158.1 kg (24 st 12 lb). See the table above for every height.
Is a BMI of 50 the same for men and women?
Yes. The NHS uses the same adult BMI categories for men and women, so a BMI of 50 is severe obesity (class 3) for both. Women usually carry more body fat than men at the same BMI.
How much weight do I need to lose from a BMI of 50?
To get to a BMI of 24.9, a 5′4″ woman would need to lose about 66.3 kg (10 st 6 lb) and a 5′10″ man about 79.3 kg (12 st 7 lb). Losing 0.5 to 1 kg a week, that would take roughly 66–133 weeks for the woman. Even a 5% loss brings health benefits.
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Medical disclaimer: this guide is general information for adults and is not a diagnosis or medical advice. bmicalculatornhs.net is independent and not affiliated with the NHS. Speak to your GP, pharmacist or another qualified health professional about your own health. Full disclaimer.