Stone to Kilograms

Stone to Kilograms Converter

Instantly and accurately convert human body weight and mass between Stones (st) and metric Kilograms (kg).

Live Weight Calculator
Invalid Number
Important: Decimals in stones do not directly equal pounds! Because 1 stone equals 14 lbs, entering 10.5 stones physically equals 10 stones and 7 pounds, not 10 stones and 5 pounds.
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Current Calculation (st to kg)
10 st × 6.35029 = 63.5029 kg
Inverse: 63.5029 kg ÷ 6.35029 = 10 st

Understanding Stone to Kilograms Conversions

Our premium Stone to Kilograms Converter is a highly precise, bidirectional tool designed to help you quickly translate human body weight measurements. Whether you are tracking personal fitness goals, managing medical health records, or simply translating UK measurements into the standard metric system, this calculator provides instant, exact mathematical results.

What is a Stone (st)?

The stone (st) is an Imperial unit of mass predominantly utilized in the United Kingdom and Ireland for measuring human body weight. Historically, it was based on the weight of a physical stone utilized for trade across Europe. Today, the unit is strictly standardized: 1 stone is exactly equal to 14 pounds (lbs).

While the United Kingdom officially adopted the metric system decades ago, the stone remains deeply ingrained in everyday British culture. It is incredibly common for individuals to state their weight as "11 stone 4" (meaning 11 stones and 4 pounds).

What is a Kilogram (kg)?

The kilogram (kg) is the foundational base unit of mass in the International System of Units (SI). It is the global standard for measuring weight and mass in science, industry, medicine, and daily life in nearly every country outside of the US and UK.

The Mathematical Conversion Formulas

The mathematical conversion between these two units relies on the internationally agreed-upon definition of a pound. Since exactly 1 pound equals 0.45359237 kg, and 1 stone equals exactly 14 pounds, the exact conversion factor becomes 6.35029318.

Stone to Kilograms Formula:
To convert to kilograms, multiply your weight in stones by 6.35029.
kg = st × 6.35029

Kilograms to Stone Formula:
To convert to stones, divide your weight in kilograms by 6.35029.
st = kg ÷ 6.35029

Standard Body Weight Conversion Table

Below is a quick reference table for common adult body weights, displaying exactly how stones relate to pounds and their metric kilogram equivalent.

Stones (st) Pounds (lbs) Kilograms (kg)
1 st 14 lbs 6.35 kg
8 st 112 lbs 50.80 kg
10 st 140 lbs 63.50 kg
12 st 168 lbs 76.20 kg
14 st 196 lbs 88.90 kg
16 st 224 lbs 101.60 kg

Frequently Asked Questions (FAQ)

How many kilograms are in exactly 1 stone?

One stone is exactly equal to 6.35029318 kilograms. For practical everyday use in fitness and medicine, it is almost always rounded to two decimal places: 6.35 kg.

How do I convert "Stones and Pounds" to Kilograms?

To use a decimal-based calculator, you must first convert your "stones and pounds" into a single decimal stone format. Because there are 14 pounds in a stone, divide your remaining pounds by 14. For example, if you weigh 10 stone 7 lbs, divide 7 by 14 to get 0.5. Your total weight is 10.5 stones. Multiply 10.5 by 6.35029 to get your kilograms.

Is the Stone measurement utilized outside the UK?

Generally, no. The stone is almost exclusively utilized in the United Kingdom and Ireland to measure human body weight. The United States uses pounds (lbs) exclusively for body weight, while the rest of the world uses metric kilograms (kg).