Carats to Stone (ct to st) Converter

How to convert carats to stone

Formulast = ct × 0.00003149460888

Multiply the value in carats by 0.00003149460888. To go the other way, multiply by 31,751.4659 (or divide by 0.00003149460888).

A carat is smaller than a stone: it takes 31,751.4659 carats to make one stone.

Worked examples

1 carat1 ct × 0.00003149460888 = 0.00003149460888 st
5 carats5 ct × 0.00003149460888 = 0.0001574730444 st
10 carats10 ct × 0.00003149460888 = 0.0003149460888 st
20 carats20 ct × 0.00003149460888 = 0.0006298921777 st
100 carats100 ct × 0.00003149460888 = 0.003149460888 st

Carats to stone conversion table

Values are calculated by the conversion engine and rounded to 8 significant figures.

Carats to stone: 0.1–10 ct
Carats (ct)	Stone (st)
0.1 ct	0.0000031494609 st
0.25 ct	0.0000078736522 st
0.5 ct	0.000015747304 st
1 ct	0.000031494609 st
2 ct	0.000062989218 st
3 ct	0.000094483827 st
4 ct	0.00012597844 st
5 ct	0.00015747304 st
6 ct	0.00018896765 st
7 ct	0.00022046226 st
8 ct	0.00025195687 st
9 ct	0.00028345148 st
10 ct	0.00031494609 st

Carats to stone: 12–1,000 ct
Carats (ct)	Stone (st)
12 ct	0.00037793531 st
15 ct	0.00047241913 st
20 ct	0.00062989218 st
25 ct	0.00078736522 st
30 ct	0.00094483827 st
40 ct	0.0012597844 st
50 ct	0.0015747304 st
75 ct	0.0023620957 st
100 ct	0.0031494609 st
250 ct	0.0078736522 st
500 ct	0.015747304 st
1,000 ct	0.031494609 st

About the units

Carat (ct)

The metric carat is exactly 200 mg and is used to weigh gemstones. (Karat, a gold-purity scale, is a different thing.) One carat equals 0.0002 kilograms (kg).

Stone (st)

Fourteen pounds (6.35029318 kg). Body weight in the UK and Ireland is often quoted in stones and pounds.

Frequently asked questions

How many stone are in one carat?

There are 0.00003149460888 stone in one carat, and this value is exact by definition.

How do I convert carats to stone?

Multiply the number of carats by 0.00003149460888. For example, 10 ct × 0.00003149460888 = 0.0003149460888 st.

How many carats are in one stone?

One stone equals 31,751.4659 carats. That is the reverse factor, 1 ÷ 0.00003149460888.

What is 10 carats in stone?

10 ct = 0.0003149460888 st.

Is this ct to st converter accurate?

Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.

Carats to Stone Converter