How many kg is 1 stone?

One stone equals exactly 6.35029 kilograms. So 10 stone is 63.5 kg, 12 stone is 76.2 kg, and 15 stone is 95.3 kg. The stone is a uniquely British measurement containing exactly 14 pounds.

How do I convert stone and pounds to kg together?

First convert everything to pounds (stone x 14 + extra pounds), then multiply by 0.453592 to get kilograms. For example, 11 stone 4 lbs = (11 x 14) + 4 = 158 lbs = 158 x 0.453592 = 71.67 kg. This converter does the calculation automatically.

Why do gym scales often show kg instead of stone?

Most gym equipment is manufactured internationally and calibrated in kilograms, which is the global standard for mass measurement. Many UK gyms import equipment from companies that default to metric. Some scales offer both options, but digital equipment increasingly uses kg only.

Stone to Kilograms Converter

Convert stone and pounds to kilograms, or kilograms to stone

Published by UltraCalculatorsLast reviewed: 1 Apr 2026v1.0Report an issue

For anyone in the United Kingdom who tracks their weight, converting between stone and kilograms is a regular necessity. You step on the bathroom scales and see a number in kilograms, but your mental framework thinks in stone and pounds. Or you need to fill in a medical form with your weight in kilograms, and you only know it in stone. This back-and-forth is a constant feature of British life. One stone equals exactly 6.35029 kilograms. The stone, which contains 14 pounds, has been used in the British Isles for centuries and remains the dominant way people discuss body weight in conversation, even though official contexts like the NHS and pharmaceutical dosing use kilograms. This dual system means that being able to convert accurately is genuinely practical. This converter works in both directions. Enter your weight in stone and pounds to get the kilogram equivalent for medical forms, gym equipment, or international contexts. Or enter a kilogram figure to translate it into the stone and pounds format that most British people naturally understand.

How to Use This Calculator

To use the stone to kilograms converter: 1. Select the conversion direction. Choose "Stone and Pounds to Kilograms" if you know your weight in imperial and need the metric equivalent. Choose "Kilograms to Stone and Pounds" for the reverse. 2. For stone to kg: Enter the stone value and any additional pounds separately. For example, for 12 stone 7, enter 12 in stone and 7 in pounds. 3. For kg to stone: Enter the kilogram value. The converter breaks the result into whole stone and remaining pounds. 4. Results include the total in grams, which can be useful for precise tracking or medical purposes.

How It Works

The conversion uses the standard definitions: 1 stone = 6.35029 kg, 1 pound = 0.453592 kg. Stone and Pounds to Kilograms: kg = (stone x 6.35029) + (pounds x 0.453592) Example: 12 st 7 lbs = (12 x 6.35029) + (7 x 0.453592) = 76.203 + 3.175 = 79.378 kg Kilograms to Stone and Pounds: Total stone (decimal) = kg / 6.35029 Whole stone = floor of total stone Remaining pounds = (decimal part) x 14 Example: 85 kg = 85 / 6.35029 = 13.385 st = 13 st 5.4 lbs

Worked Examples

Example 1: Filling in a GP registration form

Inputs: Stone: 14. Pounds: 2. Direction: stone to kg.

Kilograms from stone: 14 x 6.35029 = 88.904 kg.
Kilograms from pounds: 2 x 0.453592 = 0.907 kg.
Total: 88.904 + 0.907 = 89.811 kg.

Result: 14 stone 2 pounds equals 89.8 kg. This would be entered as 89.8 or 90 on a medical form.

Example 2: Reading gym scales after a workout

Inputs: Kilograms: 72.5. Direction: kg to stone.

Total stone: 72.5 / 6.35029 = 11.416 stone.
Whole stone: 11.
Remaining pounds: 0.416 x 14 = 5.8 lbs.

Result: 72.5 kg equals 11 stone 5.8 pounds.

Example 3: Tracking weight loss progress

Inputs: Stone: 16. Pounds: 0. Then Stone: 14. Pounds: 7.

Starting weight: 16 x 6.35029 = 101.605 kg.
Current weight: (14 x 6.35029) + (7 x 0.453592) = 88.904 + 3.175 = 92.079 kg.
Weight lost: 101.605 - 92.079 = 9.526 kg.

Result: Losing 1 stone 7 lbs (from 16st to 14st 7lbs) is a loss of 9.53 kg.

Quick reference chart: 8 st = 50.8 kg, 9 st = 57.2 kg, 10 st = 63.5 kg, 11 st = 69.9 kg, 12 st = 76.2 kg, 13 st = 82.6 kg, 14 st = 88.9 kg, 15 st = 95.3 kg, 16 st = 101.6 kg, 17 st = 108.0 kg, 18 st = 114.3 kg, 20 st = 127.0 kg. Each stone is exactly 14 pounds, and each pound is approximately 0.4536 kg.