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Kilograms to Stones

1 Kilogram (kg) = 0.157473Stone (st)

Last updated: Reviewed by James Whitfield , Physical Sciences Specialist
Accuracy verified. Conversions on this page are calculated against SI (BIPM) and NIST standards and reviewed for correctness.
Result
0.157473 st
1 kg = 0.157473 st

How Many Stones in a Kilogram?

1 kilogram equals 0.157473 stones. To convert kilograms to stones, divide by 6.35029 or multiply by 0.157473. This conversion is primarily needed when communicating body weight with people in the United Kingdom or Ireland, where stones remain the dominant everyday unit for personal weight despite the UK's official metrication more than 30 years ago. If a European doctor tells you that you weigh 85 kg and you relay that to a British relative, they may struggle to picture it. Expressed as 13 stone 5 lbs, the weight instantly makes sense in British cultural terms. Stones are unusual as a weight unit because they are almost always used as a compound measurement — body weight is expressed in stones and pounds together (for example, '11 stone 4 lbs'), not as a decimal. So converting kilograms to stones requires two steps: first dividing by 6.35029 to get the total stones as a decimal, then separating the whole stones from the fractional remainder and multiplying the remainder by 14 to get the extra pounds. This two-step process is unfamiliar to people outside the UK, but it is essential for communicating body weight naturally in a British context. Doctors' offices, British tabloids, fitness magazines, bathroom scale displays, boxing weight classes, and horse racing all use the stones-and-pounds format, making this conversion genuinely useful for anyone interacting with British culture around health, sport, or lifestyle.

How to Convert Kilogram to Stone

  1. Start with your weight in kilograms (kg).
  2. Divide by 6.35029 to get the total weight in stones as a decimal.
  3. The whole number before the decimal point is the stones.
  4. Multiply the decimal portion by 14 to get the remaining pounds.
  5. Express the result as 'X stone Y lbs'. For example: 80 kg ÷ 6.35029 = 12.598 st. 12 stone. 0.598 × 14 = 8.37 lbs → 12 stone 8 lbs.
  6. For a quick estimate, divide kg by 6.35 — or round down to the nearest whole stone and use the known conversions: 10 st = 63.5 kg, 11 st = 69.9 kg, 12 st = 76.2 kg.

Real-World Examples

Body weight: A 70 kg person expressing their weight in British terms
70 ÷ 6.35029 = 11.02 st, or 11 stone 0 lbs (exactly 11 stone, a clean benchmark)
Medical form: Converting 90 kg for a UK health record
90 ÷ 6.35029 = 14.17 st. 0.17 × 14 = 2.4 lbs, so about 14 stone 2 lbs
Weight loss: You've lost 10 kg on a diet and want to tell a British friend
10 ÷ 6.35029 = 1.57 st. 0.57 × 14 = 8 lbs, so you've lost about 1 stone 8 lbs
Boxing weight class: A fighter weighing 63.5 kg
63.5 ÷ 6.35029 = 10.0 st — exactly 10 stone, the welterweight limit in traditional British boxing
Baby milestone: A toddler weighing 12 kg
12 ÷ 6.35029 = 1.89 st. 0.89 × 14 = 12.5 lbs, so approximately 1 stone 12½ lbs.
Rugby player targeting a weight gain to 100 kg
100 ÷ 6.35029 = 15.75 st. 0.75 × 14 = 10.5 lbs, so 15 stone 10½ lbs — a common UK performance milestone in rugby and strength sports.

Quick Reference

Kilogram (kg)Stone (st)
10.157473
20.314946
50.787365
101.57473
253.93683
507.87365
10015.7473
50078.7365
1,000157.473

Related Converters

History of Kilogram and Stone

The stone has been used as a unit of weight in the British Isles since at least the 14th century. Originally, its value varied dramatically depending on the commodity being weighed and the region — a stone of wool weighed 14 pounds, a stone of beef weighed 8 pounds, a stone of hemp weighed 32 pounds, and a stone of glass weighed 5 pounds. The 14-pound standard was formalized for general use by an Act of Parliament in 1389 under King Richard II, specifically to regulate the wool trade and prevent fraud by merchants. This 14-pound stone became the dominant standard for body weight across the British Isles. The stone's cultural persistence in Britain is remarkable. Despite the UK officially adopting the metric system in 1985 and teaching metric measurements in schools ever since, British adults continue to give their body weight in stones and pounds rather than kilograms. Horse racing uses stone and pounds for jockey weights ('the jockey rode at 8 stone 7 lbs'). Boxing weight classes in the UK are still defined in stones (for example, heavyweight begins at 14 stone 4 lbs). NHS health charts and GP consultations routinely display body weight in both stones and kilograms. British bathroom scales typically offer stones/lbs, kilograms, and pounds as display modes. The UK government has never mandated the use of kilograms for body weight, leaving stones in a cultural gray zone that persists across generations. The kilogram, defined during the French Revolution and redefined in 2019 using the Planck constant, is the SI standard used by virtually every other country for body weight.

Common Mistakes to Avoid

  • Forgetting that stones have 14 pounds, not 10. When converting the decimal remainder to pounds, multiply by 14, not 10 or 16. For example, 0.5 stones = 7 lbs, not 5 lbs.
  • Reporting just the stone value without the remaining pounds. Saying '11.8 stones' is unusual in British usage — the correct format is '11 stone 11 lbs'.
  • Using the stones-to-kg conversion factor (6.35) as a multiplier instead of a divisor. To go from kg to stones, the number should get smaller, not larger.

Frequently Asked Questions

How many stones is 100 kg?
100 kg = 15.75 stones, or 15 stone 10.5 lbs. This is about 220 lbs. In the UK, 100 kg is considered a significant weight threshold.
How do I express kg in stones and pounds?
Divide the kg by 6.35029 to get total stones. Take the whole number as stones. Multiply the decimal part by 14 to get pounds. For example, 82 kg ÷ 6.35029 = 12.91 stones. 0.91 × 14 = 12.7, so 82 kg = 12 stone 12.7 lbs, typically rounded to 12 stone 13 lbs.
Is there a quick way to convert kg to stones mentally?
Divide the kg value by 6.5 for a rough estimate. This overestimates by about 2%, which is close enough for casual conversation. For example, 80 kg ÷ 6.5 ≈ 12.3 stones (actual: 12.6 stones).
Do any countries besides the UK use stones?
Ireland also uses stones for body weight. Australia and other Commonwealth nations used stones historically but have fully switched to kilograms. Today, stones are effectively a UK and Irish unit only.
What is 80 kg in stones and pounds?
80 kg = 12 stone 8 lbs. Working it out: 80 ÷ 6.35029 = 12.598 stones. The whole number is 12 stone. The decimal 0.598 × 14 = 8.37, so about 8 lbs. Result: 12 stone 8 lbs (often written 12st 8lb). Other common conversions: 70 kg = 11st 0lb, 75 kg = 11st 11lb, 90 kg = 14st 2lb, 100 kg = 15st 10lb.
Why does the UK still use stones for body weight?
Cultural inertia and generational habit. Stones became deeply embedded in British daily life for body weight long before the metric system arrived. Bathroom scales, NHS weight charts, and everyday conversation all historically used stones and pounds. Even after metrication, adults who grew up with stones continued using them, and the habit passed down. The UK government never mandated metric for body weight the way it did for trade goods, leaving stones in a cultural gray zone that persists today.
Quick Tip

A practical anchor table for kg-to-stones: 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. Each additional stone adds 6.35 kg or 14 lbs. Memorizing the anchor of 10 stone = 63.5 kg = 140 lbs lets you quickly estimate any other value by adding or subtracting stones. For example, if someone says they are 'about 13 stone,' you know they weigh approximately 82.6 kg — without doing any division.

Common Weight Reference

A loaf of bread ≈ 450 g (1 lb). A gallon of water ≈ 3.78 kg (8.34 lb). An average adult ≈ 70–80 kg (154–176 lb). A compact car ≈ 1,400 kg (3,086 lb).

Further Reading

Sources & References