Stone to Kilograms Converter

How to Convert Stone to Kilograms?

Multiply the weight in stone by 6.35029 to get kilograms. One stone equals 6.35029 kg (14 pounds). Conversely, one kilogram equals 0.15747 stone. A person weighing 10 stone is 63.5 kg (140 lbs). A person weighing 12 stone 7 pounds is 79.4 kg (175 lbs). Enter any weight in the converter above for instant conversion between stone, kilograms, and pounds in all directions.

Stone to Kg Reference Table

7 stone = 44.5 kg = 98 lbs. 8 stone = 50.8 kg = 112 lbs. 9 stone = 57.2 kg = 126 lbs. 10 stone = 63.5 kg = 140 lbs. 11 stone = 69.9 kg = 154 lbs. 12 stone = 76.2 kg = 168 lbs. 13 stone = 82.6 kg = 182 lbs. 14 stone = 88.9 kg = 196 lbs. 15 stone = 95.3 kg = 210 lbs. 16 stone = 101.6 kg = 224 lbs. 17 stone = 108.0 kg = 238 lbs. 18 stone = 114.3 kg = 252 lbs. 20 stone = 127.0 kg = 280 lbs. For stone-and-pounds combinations, multiply the stone by 6.35 and add the pounds converted to kg (pounds times 0.4536).

Where Is the Stone Unit Used?

The stone is primarily used in the United Kingdom and Ireland for measuring body weight. British and Irish people commonly say "I weigh 11 stone" rather than 70 kg or 154 pounds. The unit also appears in horse racing (jockeys' weights) and boxing (weight classes in British boxing). Australia and Canada historically used stone but have largely switched to kilograms following metrication. The stone is not used in the United States (which uses pounds) or in most of continental Europe (which uses kilograms). This makes stone-to-kg conversion essential for British and Irish travelers, expatriates, and anyone interacting with UK health services.

Stone-and-Pounds: Mixed Unit Conversion

British weights are often expressed in stone and pounds together: "11 stone 4 pounds" means 11 full stone plus 4 additional pounds. To convert to kg: (11 times 6.35029) + (4 times 0.45359) = 69.85 + 1.81 = 71.67 kg. To convert kg to stone and pounds: divide kg by 6.35029 for total stone, take the whole number as stone, multiply the decimal remainder by 14 for pounds. For 75 kg: 75 / 6.35029 = 11.81 stone = 11 stone and (0.81 times 14) = 11.3 pounds, so approximately 11 stone 11 pounds.

BMI and Medical Weight in Different Units

Body Mass Index (BMI) uses kilograms and meters: BMI = weight(kg) / height(m)². UK doctors often receive patient weights in stone and must convert to kilograms for BMI calculation and drug dosing. A patient reporting "13 stone 5" needs conversion to 84.8 kg before calculating BMI or medication dosages. NHS health guidelines reference both stone and kg. Online BMI calculators and fitness apps increasingly accept all three units (stone, kg, lbs), but understanding the conversion yourself helps verify calculations and communicate your weight accurately in any medical context worldwide.

History of the Stone

The stone has been used as a unit of weight in the British Isles for centuries, though its value varied by commodity and region. A stone of wool differed from a stone of beef. Parliament standardized the stone at 14 pounds in 1835 through the Weights and Measures Act. Despite UK metrication efforts since the 1960s, the stone persists in everyday speech for body weight, much like Americans continue using Fahrenheit. The unit's survival reflects cultural attachment to traditional measurement language. Younger Britons increasingly use kilograms, but stone remains dominant in casual conversation, media weight reports, and weight loss discussions throughout the UK and Ireland.

Stone in Boxing and Horse Racing

British boxing weight classes historically used stone: flyweight (8 stone), lightweight (9 stone 9 lbs), welterweight (10 stone 7 lbs), middleweight (11 stone 6 lbs), heavyweight (no upper limit). International boxing now uses pounds or kilograms. Horse racing still uses stone extensively in the UK and Ireland for jockey and handicap weights. A jockey might need to "make weight" at 8 stone 7 lbs (54 kg / 119 lbs). Trainers and handicappers assign weights in stone and pounds that horses must carry during races. This tradition maintains the stone's relevance in one of Britain's oldest and most tradition-bound sports.

Frequently asked questions