# Carats to Stones (ct to st)

Source: https://www.unitconvertercalculator.com/weight/carats-to-stones/

**1 ct = 3.1494608883554E-5 st**

One carat equals approximately 0.00003149 stones. The stone is a British unit of weight equal to 14 pounds (about 6.35 kilograms), still widely used in the UK and Ireland for measuring human body weight. At roughly 31,751 carats per stone, the conversion highlights the enormous gap between gemstone and body-weight scales.

## Formula

Apply the conversion factor

## Conversion Table

| Carats (ct) | Stones (st) |
|---|---|
| 100 ct | 0.0031494608883554 st |
| 500 ct | 0.015747304441777 st |
| 1000 ct | 0.031494608883554 st |
| 5000 ct | 0.15747304441777 st |
| 10000 ct | 0.31494608883554 st |
| 25000 ct | 0.78736522208885 st |
| 50000 ct | 1.5747304441777 st |
| 100000 ct | 3.1494608883554 st |
| 500000 ct | 15.747304441777 st |
| 1000000 ct | 31.494608883554 st |

## Units

### Carat (ct)

A carat is a unit of mass equal to exactly 200 milligrams (0.2 grams), used for measuring gemstones and pearls. Adopted internationally in 1907 by the Fourth General Conference on Weights and Measures.

### Stone (st)

A British unit of mass equal to 14 pounds or approximately 6.35 kilograms. Commonly used in the UK and Ireland for body weight.

## Background

When a British person says they weigh '10 stone 7,' they mean 147 pounds or about 66.7 kilograms - roughly 333,390 carats. The stone remains the preferred unit for body weight in everyday British conversation, despite the metric system being official. Converting carats to stones is most likely to arise in humorous contexts or when gemstone enthusiasts want to express their collection weight in relatable British terms.

## Good to Know

The stone's persistence in British culture is remarkable. While Britain officially adopted the metric system for trade in 2000, human body weight remains a stronghold of the stone. NHS health guidelines include stone measurements alongside kilograms. Weight Watchers (now WW) programs in the UK track progress in stones and pounds. The stone occupies a uniquely personal space in British identity - asking someone's weight 'in kilos' still feels foreign to many Britons.

## FAQ

### How many carats are in one stone?

One stone (14 pounds or 6.35 kg) equals approximately 31,751 carats. This comes from 6,350.29 grams divided by 0.2 grams per carat.

### Why is a stone 14 pounds?

The 14-pound stone was standardized in 1835 by the British Weights and Measures Act. Before this, the stone varied by commodity: a stone of wool was 14 pounds, but a stone of glass was 5 pounds, and a stone of sugar was 8 pounds. The 1835 act fixed all stones at 14 pounds.

### Do Americans use stones?

Generally no. Americans use pounds for body weight, while Britons and Irish people use stones and pounds. A British '11 stone' is an American '154 pounds.' The stone is essentially unknown in American measurement culture.

## Non-Frequently Asked Questions

### If I weigh 12 stone, how many carats of diamond is my body weight?

Twelve stone (168 pounds, 76.2 kg) equals about 381,016 carats. If you were made of diamonds instead of flesh and bone, you would be worth billions of dollars. You would also have significant difficulty with basic motor functions, since diamonds do not bend.

### If I threw a stone, would it weigh one stone?

The average throwing stone weighs perhaps 200 to 500 grams (1,000 to 2,500 carats), while the unit 'stone' weighs 6,350 grams (31,751 carats). Your thrown stone is about 3 to 8 percent of a measurement stone. The homonym is pure coincidence - the unit was named after actual heavy stones used as counterweights on scales.

### Why do British people refuse to say their weight in kilograms?

Cultural inertia. The stone has been used for body weight in Britain for centuries, and habits around personal measurements are among the last to change. Many Britons could not immediately tell you their weight in kilograms despite using metric units for everything else. The stone persists in bathroom scales, doctor's offices, and weight loss goals.

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## See Also

- [Stones to Carats](https://www.unitconvertercalculator.com/weight/stones-to-carats/)