Convert Stones (st) to Kilograms (kg)
1 stone equals 6.35029 kilograms.
Stone to Kilogram Converter
What Is a Stone?
The stone (st) is a traditional British unit of mass equal to exactly 14 pounds (6.35029318 kg). It remains the everyday unit for body weight in the United Kingdom and Ireland, even though official records use kilograms.
What Is a Kilogram?
The kilogram (kg) is the SI base unit of mass, defined since 2019 by the Planck constant. It is the international standard for mass in science, medicine, engineering, and commerce worldwide.
Stone to Kg Formula
The conversion factor is exact:
kilograms = stones × 6.35029318 exact
This comes from the definition: 1 stone = 14 lb, and 1 lb = 0.45359237 kg, so 14 × 0.45359237 = 6.35029318 kg exactly.
Worked Example
Convert 11 stone to kilograms:
- Multiply: 11 × 6.35029 = 69.85 kg
So 11 stone ≈ 69.9 kg — a common body weight value in the UK.
Quick Estimation
Multiply stones by 6.35. Quick anchors: 8 st = 50.8 kg, 10 st = 63.5 kg, 12 st = 76.2 kg, 14 st = 88.9 kg, 16 st = 101.6 kg. For stones and pounds: convert stones to kg, then add pounds × 0.454.
Need to convert stones and pounds together (e.g., 11 st 6 lb)? Use our stones and pounds to kg converter for combined st + lb inputs.
Where Are Stones Still Used?
- UK daily life: "I weigh 11 stone" is standard conversation. Official NHS records use kg.
- NHS and medical: Patients report in stones, doctors record in kg. NHS apps show both.
- Fitness tracking: International apps use kg. "Lose 1 stone" = lose 6.35 kg or 14 lbs.
- Ireland: Like the UK, stones are used colloquially despite metric adoption.
Frequently Asked Questions
How many kilograms are in a stone?
1 stone = exactly 6.35029318 kg (14 pounds). To convert, multiply stones by 6.35.
Do UK doctors use stones or kilograms?
Medical records use kg (SI standard). Patients describe weight in stones. NHS websites show both formats.
What is a healthy weight in stones?
Roughly 9–12 stone (57–76 kg) for average-height women and 10–13 stone (63–83 kg) for men. Use a BMI calculator for personalised guidance.
Why does only the UK use stones?
The stone was used across the British Empire. Most former colonies switched to metric. The UK officially adopted metric in 1965 but retained stones in everyday speech — a cultural habit.
Common Stone to Kilogram Conversions
Stones to kilograms Conversion Table
Reference table with common stones to kilograms conversions. All values calculated with high precision.
Stones to Kilograms Table
0.0001 to 12
Stones to Kilograms Table
1 to 100000
Kilograms to Stones Table
0.001 to 5
Kilograms to Stones Table
10 to 1000000
Looking for the reverse? Convert Kilogram to Stone
Related Weight (Mass) Converters
Explore other weight (mass) conversion tools:
Need a combined format?
- Kg to Pounds and Ounces — combined lb + oz format
- Kg to Stones and Pounds — UK body weight format
Related in other categories:
- G-force to m/s² — Force = mass × acceleration (F = ma)
