Kilograms to Stone & Pounds Converter (kg to st)

How to Convert Kilograms to Stone & Pounds

One stone equals 6.35029 kilograms, or equivalently, one kilogram equals 0.157473 stone. To convert:

Kilograms to Stone & Pounds — Body Weight Chart

Imperial Weight Units — Complete Hierarchy

What Is a Kilogram?

The kilogram (kg) is the SI base unit of mass. It equals 1,000 grams, approximately 2.205 pounds, or 0.157 stone. Since 2019, the kilogram is defined using the Planck constant. The kilogram is used worldwide — it's the standard unit for body weight in most countries outside the US, UK, and a few others.

What Is a Stone?

A stone (st) is an imperial unit of weight equal to exactly 14 pounds or approximately 6.35 kilograms. It originated in medieval England as a unit for weighing commodities like wool. Today it's primarily used for body weight in the United Kingdom and Ireland. One stone is 14 pounds — making it a convenient "package" of pounds for expressing human weight.

Where Is Stone Still Used?

• United Kingdom: Most British people express body weight in stone and pounds (e.g., "I weigh 11 stone 6").
• Ireland: Same convention as the UK — stone and pounds for body weight.
• Australia: Older Australians may still use stone, though kilograms are now the official standard.
• United States: Stone is not commonly used in the US — Americans typically use pounds only. However, Americans may encounter stone when communicating with British or Irish people.

Why Americans Use Pounds Instead of Stone

While both the US and UK inherited the imperial system from Britain, the US dropped the stone as a commonly used unit by the mid-1800s. Americans simplified body weight to "just pounds" — so a 154-pound person in the US would be described as "11 stone" in the UK. Neither system uses kilograms in everyday conversation, though medical records in both countries increasingly record weight in kg.

BMI Reference — Multiple Units

Body Mass Index (BMI) categories using a 5'10" (178 cm) person as an example: