Stone to kg: How to Convert Stone and Pounds to Kilograms | All Units Converter
Published on May 2, 2026
If you’ve ever seen a UK bathroom scale or a British medical chart, you’ve encountered the stone — a unit of weight still used daily across the United Kingdom and Ireland. In this guide you’ll learn the exact formula to convert stone to kg, how to handle stone and pounds together, and a full conversion chart covering the most common body weights.
What is a stone?
The stone is a unit of weight in the British Imperial system, defined as exactly 14 pounds or 6.35029 kilograms. It is used almost exclusively in the UK and Ireland, primarily for measuring human body weight — you’ll commonly hear people say “I weigh 11 stone 4” rather than stating their weight in kilograms or pounds.
Outside the UK and Ireland, the stone is rarely used. Most of the world uses kilograms (metric system), while the United States uses pounds. This is why stone-to-kg conversion matters so often — British weight records, medical charts, and fitness tracking apps frequently require switching between the two systems.
Tip: Want to convert instantly without doing the maths? Use our free Weight & Mass Converter — it handles stone, pounds, kilograms, grams and more in one click.
Stone to kg formula
The conversion from stone to kilograms uses a single, fixed multiplication factor:
Formula
kg = stone × 6.35029
Where 6.35029 is the exact number of kilograms in one stone.
To convert kilograms back to stone, divide by 6.35029:
Reverse formula
stone = kg ÷ 6.35029
Useful for converting metric body weight from a doctor’s scale back to stone.
Step-by-step worked examples
Example 1: Convert 10 stone to kg
Worked example
1Start with the value in stone: 10 stone
2Apply the formula: 10 × 6.35029
3Calculate: 63.5029 kg
10 stone = 63.50 kg
Example 2: Convert 13 stone to kg
Worked example
1Start with: 13 stone
2Apply the formula: 13 × 6.35029
3Calculate: 82.5538 kg
13 stone = 82.55 kg
Stone to kg conversion chart
This reference chart covers the most common body weight values from 6 stone to 25 stone:
Stone
Pounds (lbs)
Kilograms (kg)
6 st
84 lb
38.10 kg
7 st
98 lb
44.45 kg
8 st
112 lb
50.80 kg
9 st
126 lb
57.15 kg
10 st
140 lb
63.50 kg
11 st
154 lb
69.85 kg
12 st
168 lb
76.20 kg
13 st
182 lb
82.55 kg
14 st
196 lb
88.90 kg
15 st
210 lb
95.25 kg
16 st
224 lb
101.60 kg
17 st
238 lb
107.95 kg
18 st
252 lb
114.31 kg
20 st
280 lb
127.01 kg
25 st
350 lb
158.76 kg
Converting stone and pounds together
In the UK, weight is often expressed as a combination of stone and pounds — for example, 11 stone 7 lbs. Here’s how to convert a mixed value to kilograms in three steps:
For more complex conversions — particularly stone to grams or stone to other metric units — use our free weight converter tool, which handles all combinations automatically.
Quick mental conversion tips
When you need a rough answer without a calculator, these shortcuts work well:
Multiply stone by 6.35 for a very close approximation (accurate to within 0.05%).
Multiply stone by 6 and add 10% — e.g. 10 stone: 10 × 6 = 60, 10% of 60 = 6, total ≈ 66 kg. (Slightly overestimates by about 4%.)
Stone to lbs is easy — multiply by 14. Then convert pounds to kilograms using the 0.4536 factor.
Remember that 70 kg ≈ 11 stone — a useful anchor point for everyday estimates.
Convert stone to kg instantly
Use our free weight converter — supports stone, pounds, kg, grams, ounces and more.
Multiply the number of stone by 6.35029 to get kilograms. For example, 10 stone × 6.35029 = 63.50 kg. You can also use our free weight converter for instant results without any mental arithmetic.
1 stone is equal to exactly 6.35029 kilograms. This is also equal to 14 pounds. The conversion factor is internationally agreed and has been fixed since the Weights and Measures Act 1985 in the UK.
10 stone equals 63.50 kg (precisely 63.5029 kg). This is one of the most commonly searched conversions, as 10 stone is a common target weight for people tracking their fitness progress in the UK.
11 stone is equal to 69.85 kg (precisely 69.8532 kg). To calculate: 11 × 6.35029 = 69.8532 kg. This is approximately 154 pounds.
To convert a mixed stone-and-pounds value: multiply the stone by 6.35029, then multiply the extra pounds by 0.453592, and add both results. For example, 10 stone 5 lbs = (10 × 6.35029) + (5 × 0.453592) = 63.5029 + 2.2680 = 65.77 kg.
The stone is used almost exclusively in the United Kingdom and Ireland for measuring body weight. It is not used in the United States (which uses pounds), Australia, Canada, or mainland Europe (which all use kilograms). If you’re communicating weight internationally, kilograms or pounds are safer units.
14 stone is equal to 88.90 kg (precisely 88.9041 kg). This is equivalent to 196 pounds. At 14 stone, a person is at the upper boundary of a healthy BMI range depending on their height — though always consult a medical professional for health guidance.
One stone is exactly 14 pounds. This is a fixed, legal definition in the UK. So 10 stone = 140 lb, 11 stone = 154 lb, and 12 stone = 168 lb. To convert stone directly to pounds, simply multiply by 14. You can also use our weight converter to switch between all units at once.
