18 Stone to KG
Conversion Result
Exact Conversion
18 stone = 114.31 kg| 252 pounds
To convert any other weight from imperial to metric, you can use our primary stone to kg conversion tool for instant results.
18 stone is 114.31 kilograms. The precise calculation is 18 multiplied by 6.35029, giving 114.305, rounded to 114.31 kg. This is also 252 pounds. 18 stone is a weight that appears regularly in bariatric and weight management clinical discussions, and it is a figure that many people need to convert to kilograms when attending hospital appointments or completing medical forms.
Is This a Healthy Weight?
| Height | KG | BMI | NHS/WHO Category |
|---|---|---|---|
| 5ft 0in (152cm) | 114.31 kg | 49.5 | Obese |
| 5ft 2in (157cm) | 114.31 kg | 46.4 | Obese |
| 5ft 4in (163cm) | 114.31 kg | 43.0 | Obese |
| 5ft 6in (168cm) (UK avg) | 114.31 kg | 40.5 | Obese |
| 5ft 8in (173cm) | 114.31 kg | 38.2 | Obese |
| 5ft 10in (178cm) | 114.31 kg | 36.1 | Obese |
| 6ft 0in (183cm) | 114.31 kg | 34.1 | Obese |
| 6ft 2in (188cm) | 114.31 kg | 32.3 | Obese |
Health Context
At 18 stone, all adults at every adult height fall clearly into the obese BMI category. At 5ft 6in, 18 stone gives a BMI of 41.2, which is Class 3 obese. At 6ft 0in, the BMI is 34.8, Class 1 obese. At 6ft 4in, the BMI is approximately 31.1, still Class 1 obese. The NHS/WHO bariatric surgery threshold of BMI 40 or above is met at 18 stone for adults up to approximately 6ft 1in, making this a weight at which surgical options may be available.
Doctor’s Note
Dr Muhammad Usman, MBBS
18 stone is a weight where I think it is important to be honest without being judgmental. The clinical risks at this weight are real. The likelihood of associated conditions including sleep apnoea, Type 2 diabetes, hypertension, and joint disease is significant. But I also know that people at this weight have usually been living with these challenges for years and have often tried many interventions. What I want to focus on is what is achievable now, and in 2026 the options are genuinely better than they have ever been. Bariatric surgery remains the most effective long-term intervention for weight at this level.
Weights Close to 18 stone
| Stones & Pounds | Kilograms (kg) | Total Pounds |
|---|---|---|
| 17 st 8 lb | 111.58 kg | 246 lbs |
| 17 st 10 lb | 112.49 kg | 248 lbs |
| 17 st 12 lb | 113.40 kg | 250 lbs |
| 18 st 0 lb (This weight) | 114.31 kg | 252 lbs |
| 18 st 2 lb | 115.21 kg | 254 lbs |
| 18 st 4 lb | 116.12 kg | 256 lbs |
| 18 st 6 lb | 117.03 kg | 258 lbs |
For more weight comparisons, see our full stone to kg chart. Need to go the other way? Try our kg to stone converter. You can also check your BMI using our NHS/WHO-aligned BMI calculator.
Related Conversions
Frequently Asked Questions
What is 18 stone in kg?
18 stone is 114.31 kg. Multiply 18 by 6.35029 to get 114.305 kg, which rounds to 114.31 kg.
Is 18 stone morbidly obese?
For most adults under 6ft 1in, yes. At 5ft 6in, 18 stone gives a BMI of 41.2, which meets the threshold for Class 3 or severe obesity, sometimes called morbid obesity. At 6ft 0in, the BMI is 34.8, Class 1 obese.
What is 18 stone in pounds?
18 stone is exactly 252 pounds. One stone equals 14 pounds, so 18 multiplied by 14 equals 252.
Does the NHS/WHO offer bariatric surgery at 18 stone?
For most adults, yes. NHS/WHO bariatric surgery is typically available for adults with a BMI of 40 or above, or BMI 35 with a significant obesity-related condition. At 18 stone, adults up to around 6ft 1in will meet the BMI 40 threshold. Speak to your GP for a formal assessment.
What is 18 stone in kg and pounds?
18 stone is 114.31 kg and 252 pounds. All three values represent the same weight in different units.