Carats to stone

stone = carats × 0.00003149

How to convert carats to stone

One carat is 0.00003149 stone, so multiply the number of carats by 0.00003149. For example, 20 carats is 20 × 0.00003149 = 0.00062989 stone. To go back, divide by the same number, or multiply by 31,751.47.

Quick estimate

Multiplying by about 0.00003 gets within 4.7% of the exact answer, which is enough to check that a result makes sense.

Where it comes up

Mass conversions come up in cooking and baking, shipping and luggage limits, body weight, medicine doses and buying food by weight.

carats	stone
1 ct	0.00003149 st
2 ct	0.00006299 st
3 ct	0.00009448 st
4 ct	0.00012598 st
5 ct	0.00015747 st
6 ct	0.00018897 st
7 ct	0.00022046 st
8 ct	0.00025196 st
9 ct	0.00028345 st
10 ct	0.00031495 st
11 ct	0.00034644 st
12 ct	0.00037794 st
13 ct	0.00040943 st
14 ct	0.00044092 st
15 ct	0.00047242 st
16 ct	0.00050391 st
17 ct	0.00053541 st
18 ct	0.0005669 st
19 ct	0.0005984 st
20 ct	0.00062989 st
25 ct	0.00078737 st
30 ct	0.00094484 st
40 ct	0.00125978 st
50 ct	0.00157473 st
60 ct	0.00188968 st
70 ct	0.00220462 st
75 ct	0.0023621 st
80 ct	0.00251957 st
90 ct	0.00283451 st
100 ct	0.00314946 st
120 ct	0.00377935 st
150 ct	0.00472419 st
200 ct	0.00629892 st
250 ct	0.00787365 st
300 ct	0.00944838 st
400 ct	0.01259784 st
500 ct	0.0157473 st
750 ct	0.02362096 st
1,000 ct	0.03149461 st
1,500 ct	0.04724191 st
2,000 ct	0.06298922 st
5,000 ct	0.15747304 st
10,000 ct	0.31494609 st

Questions

How many stone are in a carat?

0.00003149 stone.

How do I convert carats to stone in a spreadsheet?

Put the value in A1 and type =A1*0.00003149, then fill the formula down the column.

Are the values in the table exact?

They are calculated from the exact definitions of the units and rounded only for display. Open any row for the full working.