Why Use a BMI Calculator in Stones and Pounds?
Most BMI calculators online are built around metric measurements — kilograms and centimetres — which reflects the international scientific standard. However, the majority of people in the United Kingdom still think about their weight primarily in stones and pounds. Ask most British adults how much they weigh, and they will answer in stone rather than kilograms, even if they know both.
This is not simply a generational habit — it is deeply embedded in everyday UK life. GP surgeries display weight in both units; bathroom scales sold in the UK almost always show stone and pounds; and conversations about weight in the UK almost universally use the imperial system. Despite metrication of most official measurements, the stone remains the most commonly understood unit of body weight in Britain.
A BMI calculator that requires you to first convert your weight into kilograms before entering it adds an unnecessary barrier. Our calculator on this page works directly in stones and pounds and feet and inches — no conversion necessary — giving you an instant, accurate result with no maths involved.
Did you know? The stone is a unit of weight unique to the United Kingdom and Ireland. It equals exactly 14 pounds or 6.35029 kilograms. While most countries use only kilograms, the stone remains the dominant way British adults measure and discuss body weight.
What Is a Healthy Weight in Stones for My Height?
Because a healthy BMI (18.5 to 24.9) covers a range rather than a single number, the healthy weight in stones depends entirely on your height. The taller you are, the more you can weigh and still be within the healthy BMI range. Below is a practical guide to healthy weight ranges in stones and pounds for common UK heights:
| Height | Minimum Healthy Weight | Maximum Healthy Weight | Overweight From |
|---|---|---|---|
| 5ft 0in (152cm) | 6st 12lb (43.5kg) | 9st 2lb (58.1kg) | 9st 3lb (58.7kg)+ |
| 5ft 2in (157cm) | 7st 4lb (46.3kg) | 9st 10lb (61.7kg) | 9st 11lb (62.3kg)+ |
| 5ft 4in (163cm) | 7st 11lb (49.4kg) | 10st 5lb (65.8kg) | 10st 6lb (66.5kg)+ |
| 5ft 6in (168cm) | 8st 3lb (52.2kg) | 11st 0lb (69.9kg) | 11st 1lb (70.3kg)+ |
| 5ft 7in (170cm) | 8st 7lb (53.5kg) | 11st 4lb (71.7kg) | 11st 5lb (72.6kg)+ |
| 5ft 8in (173cm) | 8st 11lb (55.9kg) | 11st 9lb (74.0kg) | 11st 10lb (74.8kg)+ |
| 5ft 10in (178cm) | 9st 4lb (59.2kg) | 12st 6lb (79.1kg) | 12st 7lb (79.4kg)+ |
| 6ft 0in (183cm) | 10st 0lb (63.5kg) | 13st 4lb (84.8kg) | 13st 5lb (85.3kg)+ |
| 6ft 2in (188cm) | 10st 7lb (66.7kg) | 14st 1lb (89.4kg) | 14st 2lb (89.8kg)+ |
These ranges are based on a healthy BMI of 18.5 to 24.9, in line with NHS guidelines. They apply to most white European adults aged 18 and over. For adults of South Asian, Chinese, or Black African/Caribbean heritage, the NHS recommends lower thresholds — overweight starts at BMI 23 rather than 25.
Converting Between Stones, Pounds, and Kilograms
If you ever need to convert between the imperial and metric systems, here are the key conversion facts:
- 1 stone = 14 pounds = 6.35029 kilograms
- 1 pound = 0.453592 kilograms
- 1 kilogram = 2.20462 pounds = 0.157473 stone
- 1 foot = 12 inches = 30.48 centimetres
- 1 inch = 2.54 centimetres
Quick Stone-to-Kilogram Conversion Guide
| Weight in Stone | Weight in Pounds | Weight in kg |
|---|---|---|
| 8 stone | 112 lbs | 50.8 kg |
| 9 stone | 126 lbs | 57.2 kg |
| 10 stone | 140 lbs | 63.5 kg |
| 11 stone | 154 lbs | 69.9 kg |
| 12 stone | 168 lbs | 76.2 kg |
| 13 stone | 182 lbs | 82.6 kg |
| 14 stone | 196 lbs | 88.9 kg |
| 15 stone | 210 lbs | 95.3 kg |
| 16 stone | 224 lbs | 101.6 kg |
BMI Categories Explained — What Your Result Means
Once you have calculated your BMI using stones and pounds, your result will fall into one of the following NHS categories. Here is what each one means for your health:
Underweight — BMI Below 18.5
A BMI below 18.5 is classified as underweight. In terms of typical UK weights, this means — for example — a 5ft 6in adult weighing less than approximately 8 stone 3 pounds would be underweight. Being underweight can indicate insufficient calorie or nutrient intake, an underlying medical condition, or in some cases disordered eating.
The health risks of being underweight include weakened immune function, nutritional deficiencies (particularly iron, calcium, and B vitamins), reduced bone density, fatigue, and impaired fertility. If your BMI falls in this range, please speak to your GP rather than attempting to increase your weight without professional guidance.
Healthy Weight — BMI 18.5 to 24.9
This is the range associated with the lowest risk of weight-related health conditions. Maintaining a healthy weight reduces your long-term risk of type 2 diabetes, cardiovascular disease, high blood pressure, certain cancers, and joint problems. If your BMI falls in this range, the NHS recommends maintaining it through a balanced diet and at least 150 minutes of moderate physical activity per week.
Being at the lower end versus the upper end of the healthy range can still make a practical difference — particularly regarding energy levels, cardiovascular fitness, and joint health. However, both ends of the healthy range are significantly better for long-term health than being overweight.
Overweight — BMI 25 to 29.9
The overweight category is the most common BMI category among UK adults — the average BMI for adults in England is approximately 27.5 for men and 27.1 for women, both in this range. Being overweight increases the risk of type 2 diabetes, high blood pressure, high cholesterol, sleep apnoea, and cardiovascular disease compared to being in the healthy range.
The good news is that even modest weight loss — just 5 to 10% of current body weight — can significantly reduce these risks. For a person weighing 13 stone, losing just under a stone (12–14 lbs) would achieve a clinically meaningful reduction in metabolic risk. The NHS Better Health campaign offers a free 12-week weight loss plan designed for UK adults.
Obese — BMI 30 and Above
Obesity is defined as a BMI of 30 or above and is further divided into three classes: Class I (BMI 30–34.9), Class II (BMI 35–39.9), and Class III — sometimes called morbid obesity — (BMI 40 and above). The health risks increase significantly with each class.
People in the obese range are at substantially increased risk of type 2 diabetes, heart attack, stroke, certain cancers (including breast, bowel, and kidney cancer), fatty liver disease, gallstones, sleep apnoea, and depression. NHS weight management services are available via GP referral, including Tier 2 community-based programmes with dietitian support, and in some cases weight loss medication such as Orlistat or — more recently — Wegovy (semaglutide), which is now available on the NHS for eligible patients.
NHS Support: If your BMI is in the overweight or obese range, you do not have to manage it alone. Your GP can refer you to free NHS weight management services. The NHS Better Health campaign also offers free apps, meal plans, and a 12-week weight loss programme available to everyone in England.
Limitations of BMI Calculated in Stones and Pounds
It is worth understanding that BMI — whether calculated using stones and pounds or kilograms and centimetres — gives exactly the same result. The unit of measurement used to enter the data does not affect the output; it is simply a matter of which units are more familiar to you. The limitations of BMI apply equally regardless of the units used.
Those limitations include:
- BMI cannot distinguish muscle from fat. A muscular person may have a BMI in the overweight range despite having very low body fat. This is particularly relevant for men who do regular strength training.
- BMI does not indicate fat distribution. Abdominal fat (central obesity) carries significantly higher health risk than fat stored around the hips and thighs, but BMI cannot tell the difference.
- BMI may be less accurate for older adults. As people age, muscle mass typically decreases and body fat increases, meaning an older adult may have a "healthy" BMI but a higher body fat percentage than a younger person with the same BMI.
- Different thresholds apply to some ethnic groups. As noted above, the NHS recommends lower BMI thresholds for South Asian, Chinese, and Black African/Caribbean adults.
For these reasons, the NHS recommends using BMI alongside waist circumference as a supplementary measure. For men, a waist above 94cm (37 inches) indicates elevated risk; for women, a waist above 80cm (31.5 inches) is the threshold. See our Healthy BMI Range UK page for a full explanation of these additional measures.
Important note for parents: The BMI calculator on this page uses adult BMI ranges and is designed for adults aged 18 and over. Children and teenagers should not use adult BMI categories. Visit our BMI for Children page for age and sex-specific centile-based assessment for children aged 2 to 17.
What Is the Average Weight in Stones for UK Adults?
According to NHS England Health Survey data, the average weight and height for adults in England are approximately:
- Average UK man: 5ft 9in tall (175.3cm), weighing approximately 13 stone 3 pounds (83.9kg), giving an average BMI of approximately 27.3
- Average UK woman: 5ft 4in tall (163.9cm), weighing approximately 11 stone 2 pounds (70.8kg), giving an average BMI of approximately 26.3
Both of these averages sit in the overweight BMI category (25–29.9), which reflects the broader trends in UK adult weight that have been tracked by NHS surveys over recent decades. Average weight among UK adults has increased by approximately 3 kilograms (around half a stone) since comparable surveys were conducted in the early 1990s.
It is important to emphasise, however, that the average BMI is not the same as a healthy BMI. The fact that a weight is statistically common does not mean it is without health risk. The NHS continues to define a healthy BMI as 18.5 to 24.9, regardless of population averages.
Common Questions — BMI in Stones
Below are some of the most common questions UK adults ask about their weight in stones and whether it falls within a healthy BMI range:
Is 10 stone a healthy weight?
Whether 10 stone is a healthy weight depends entirely on your height. For someone who is 5ft 4in tall, 10 stone gives a BMI of approximately 24.2 — comfortably within the healthy range (18.5–24.9). For someone who is only 4ft 11in tall, 10 stone gives a BMI of approximately 28.3, which is in the overweight range. For someone who is 5ft 8in, 10 stone gives a BMI of approximately 21.8 — healthy. Use our calculator above to check your specific result.
Is 11 stone overweight for a woman?
Again, it depends on height. For a woman who is 5ft 5in (165cm) tall, 11 stone (69.9kg) gives a BMI of approximately 25.7 — just into the overweight range. For a woman who is 5ft 7in (170cm) tall, 11 stone gives a BMI of approximately 24.1 — healthy. For a woman who is 5ft 3in (160cm), 11 stone gives a BMI of approximately 27.2 — overweight. Use the calculator to get your precise result for your specific height.
What is a healthy weight for a 5ft 5in woman in stones?
For a woman who is 5ft 5in (165cm) tall, the healthy weight range (BMI 18.5–24.9) is approximately 8 stone 7 pounds to 11 stone 3 pounds (54–71.7kg). Anything above 11 stone 3 pounds would be in the overweight range for this height.
How much should I weigh in stones if I am 6ft tall?
For an adult who is 6ft 0in (183cm) tall, the NHS healthy weight range (BMI 18.5–24.9) is approximately 10 stone 0 pounds to 13 stone 4 pounds (63.5–84.8kg). The overweight range begins at approximately 13 stone 5 pounds for this height.