Convert pounds to stones in a snap

Ever tried reading a British novel where characters "weigh 12 stone" and found yourself utterly confused? Or maybe you're tracking fitness goals with a UK-based app that uses this medieval-sounding unit? Let's demystify the pound-to-stone conversion together. While Americans measure weight purely in pounds, our friends across the pond add this extra layer of stones – and once you get the hang of it, it's actually pretty straightforward.

The magic number here is 14. That's right, one stone equals 14 pounds. This conversion has roots going back to wool trading in medieval England, but today it's mostly used for body weight measurements in Britain and Ireland. Whether you're interpreting medical charts, following a UK recipe, or just satisfying your curiosity, our converter above makes switching between these units effortless.

Unit definitions

What is a pound (lb)?

The pound, abbreviated lb from the Latin "libra," is a unit of mass used worldwide. In the avoirdupois system (common in the US and UK), one pound equals exactly 0.45359237 kilograms. You'll see it used for:

• Body weight measurements in the US
• Packaging weights in supermarkets
• Gym equipment resistance levels

Fun fact: There are actually three different pound definitions (avoirdupois, troy, and tower), but unless you're dealing with precious metals or medieval history, you're probably using avoirdupois pounds.

What is a stone (st)?

Unique to Britain and Ireland, the stone (st) serves as a middle unit between pounds and kilograms. Officially:

• 1 stone = 14 pounds
• 1 stone ≈ 6.35029 kilograms

Primarily used for:

• Personal body weight
• Veterinary animal weights
• Some sports like boxing (fighter weight classes)

The stone's persistence is fascinating – it was technically abolished in 1985 but remains deeply ingrained in British culture. When someone says "I weigh 11 stone," they're essentially saying "154 pounds" without doing mental math.

Conversion formula

The conversion between pounds and stones couldn't be simpler:

Stones = Pounds ÷ 14
Pounds = Stones × 14

Let's break this down with two examples:

1. Converting 168 pounds to stones
   168 lb ÷ 14 = 12 st
   (That's why 12 stone sounds familiar – it's exactly 168 lb)
2. Converting 8.5 stone to pounds
   8.5 st × 14 = 119 lb
   Notice how the decimal makes this easy? Half a stone is 7 lb

Conversion tables

Pounds to stones

Stones to pounds

Historical background

The stone's history is, well, set in stone – it dates back to ancient trading practices. Merchants used actual stones as counterweights for scales, with values varying by commodity and region. By the 14th century, England standardized the wool stone as 14 pounds (a convenient number for dividing cargo).

Here's where it gets quirky: different towns had their own stone weights until 1835. The London stone was 12.5 lb for produce, while the glass stone weighed 5 lb! The 14 lb version finally became official in the Weights and Measures Act of 1835.

Interesting facts

1. Human scale: The average adult male in the UK weighs about 13.16 stone (184 lb)
2. Baby weights: Newborns are measured in pounds (7-10 lb) rather than fractions of a stone
3. Sports legacy: British horse racing still uses stones in weight assignments for jockeys
4. Medical mix: UK hospitals record patient weights in kilograms but often discuss them in stones
5. Name origin: The term comes from the actual stones used as counterweights in medieval markets

FAQ