Stone to KG Calculator
Convert stone and pounds to kilograms instantly. Perfect for weight tracking, gym goals and medical appointments.
Convert your weight above for a personalised AI analysis, or ask any health or weight-related question directly.
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How to Convert Stone to KG
One stone equals exactly 6.35029 kilograms. To convert, multiply the number of stone by 6.35029 then add any extra pounds multiplied by 0.453592.
KG = (Stone × 6.35029) + (Pounds × 0.453592)
Example: 11st 6lb = (11 × 6.35029) + (6 × 0.453592) = 69.85 + 2.72 = 72.57 kg
If you only have stone with no extra pounds, simply multiply by 6.35029. For example, 10 stone = 10 × 6.35029 = 63.50 kg.
Why Do We Use Stone in the UK?
Stone is a unit of measurement with roots in medieval Britain, where merchants used stones as counterweights on scales. It became standardised at 14 pounds in the 14th century and has remained in everyday use in the UK and Ireland ever since — even as the metric system took over for most other measurements.
Most other countries measure body weight exclusively in kilograms, which is why converting stone to KG is so commonly needed — whether you're visiting a doctor abroad, using an international fitness app, or reading health research.
Stone to KG Conversion Table
| Stone | Kilograms | Pounds |
|---|---|---|
| 8st | 50.80 kg | 112 lb |
| 9st | 57.15 kg | 126 lb |
| 10st | 63.50 kg | 140 lb |
| 11st | 69.85 kg | 154 lb |
| 12st | 76.20 kg | 168 lb |
| 13st | 82.55 kg | 182 lb |
| 14st | 88.90 kg | 196 lb |
| 15st | 95.25 kg | 210 lb |
When Do You Need to Convert Stone to KG?
The most common situations where this conversion comes up:
- Medical appointments — NHS and most UK hospitals record weight in kg, so knowing your metric weight is useful
- Fitness apps and gym equipment — most apps default to kg, especially those developed outside the UK
- BMI calculation — the BMI formula requires weight in kilograms
- Travelling abroad — scales in hotels, gyms and pharmacies outside the UK will show kg
- Weight loss tracking — many plans and apps track progress in kg
FAQs
How many kg is 1 stone?
1 stone is equal to 6.35029 kilograms, or approximately 6.35 kg.
How do I convert stone and pounds to kg?
Multiply the stone by 6.35029 and add any extra pounds multiplied by 0.453592. For example, 11st 6lb = (11 × 6.35029) + (6 × 0.453592) = 72.57 kg.
How many kg is 10 stone?
10 stone equals 63.50 kg.
How many kg is 11 stone?
11 stone is equal to 69.85 kilograms.
How many kg is 12 stone?
12 stone is equal to 76.20 kilograms.
Why does the UK use stone for weight?
Stone has been used in Britain since medieval times and became standardised at 14 pounds in the 14th century. It remains in everyday use in the UK and Ireland despite the metric system being adopted for most other measurements.
Is this calculator free?
Yes completely free with no sign-up needed.