Carat to Stone Converter
Weight · unit-converter
Convert Carat to Stone with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations use gram-based factors (international avoirdupois pound and metric definitions). The full Weight Converter also includes carat, grain, and US/UK hundredweight.
Calculator
From: Carat (ct)
To: Stone (st)
About Carat
The metric carat is exactly 0.2 grams (200 mg), commonly used for gemstones and jewelry.
About Stone
The stone is 14 pounds (UK and Ireland). It is often used for human body weight in those regions.
How to convert carats to stone
1 carat is equal to 0.00003149460888 stone:
1 ct = (0.2 g ÷ 6350.29318 g) st = 0.00003149460888 st
Each carat is defined as 0.2 g and each stone as 6350.29318 g, so one ct equals 0.2 ÷ 6350.29318 st = 0.00003149460888 st.
Let w(ct) be the numeric value of the same mass measured in Carat (ct), and w(st) the value in Stone (st). Then:
w(st) = w(ct) × (0.2 / 6350.29318)
Equivalently, divide by how many ct fit into one st (grams per st divided by grams per ct):
w(st) = w(ct) ÷ 31751.4658999999956
Or: stone = carat ÷ 31751.4658999999956
Examples
Example #1: Convert 20 ct to stone
20 ct = 20 ct × (0.2/6350.29318) st = 0.0006298922 st
20 ct = 20 ct ÷ 31751.4658999999956 = 0.0006298922 st
Example #2: Convert 50 ct to stone
50 ct = 50 ct × (0.2/6350.29318) st = 0.0015747304 st
50 ct = 50 ct ÷ 31751.4658999999956 = 0.0015747304 st
Summary
To convert Carat to Stone, multiply the value in ct by the ratio of grams per ct divided by grams per st. Equivalently: value_st = value_ct × (0.2 / 6350.29318). Numerically, 1 ct equals 0.00003149460888355394 st.
Relationship context
You are converting between metric (SI) (Carats) and imperial / UK (stone, long ton, pound, ounce) (Stone). Metric mass is decimal from the gram; US and imperial masses use pounds and ounces with fixed definitions relative to the kilogram. The numeric factor used here is 3.149461e-5.
Conversion tables
| Carat (ct) | Stone (st) |
|---|---|
| 0.1 | 0.0000031495 |
| 1 | 0.0000314946 |
| 2 | 0.0000629892 |
| 3 | 0.0000944838 |
| 4 | 0.0001259784 |
| 5 | 0.000157473 |
| 6 | 0.0001889677 |
| 7 | 0.0002204623 |
| 8 | 0.0002519569 |
| 9 | 0.0002834515 |
| Carat (ct) | Stone (st) |
|---|---|
| 10 | 0.0003149461 |
| 20 | 0.0006298922 |
| 30 | 0.0009448383 |
| 40 | 0.0012597844 |
| 50 | 0.0015747304 |
| 60 | 0.0018896765 |
| 70 | 0.0022046226 |
| 80 | 0.0025195687 |
| 90 | 0.0028345148 |
| 100 | 0.0031494609 |