Weight conversion
Carat to Stone converter
Convert ct to st instantly, choose the displayed precision, and verify the result with the formula and reference table below.
Stone (st)
Rounded for display only; calculations retain full precision.
Rounding and precision rules
- Convr calculates first and rounds the displayed result only once, at the final step.
- The default is a maximum of 6 decimal places; trailing zeros are removed.
- Very small values that would appear as zero, and values of 10¹² or more, use scientific notation.
- Display precision is not measurement uncertainty. For scientific, engineering, or regulated work, retain only the digits justified by the source measurement.
Calculation
Carat to Stone formula
st = ct × 0.000031
Calculations retain full precision and the result is rounded only for display.
Worked example
For 10 ct, the result is 0.000315 st. Substitute 10 ct into the formula to obtain 0.000315 st.
A numerical value expressed in stone is usually smaller than the same measurement expressed in carat, because 1 ct equals 0.000031 st.
Carat to Stone reference table
Common values rounded to a maximum of 6 decimal places.
| Carat (ct) | Stone (st) |
|---|---|
| 1 ct | 0.000031 st |
| 5 ct | 0.000157 st |
| 10 ct | 0.000315 st |
| 50 ct | 0.001575 st |
| 100 ct | 0.003149 st |
Understanding the units
About Carat and Stone
Carat (ct)
One carat (ct) equals 0.0002 kg, the base relationship used for this weight conversion.
Stone (st)
One stone (st) equals 6.35029318 kg, the base relationship used for this weight conversion.
When this conversion is useful
Carat to Stone conversion is useful for shipping, recipes, product specifications, laboratory work, and body-weight records. It lets you compare the same mass or weight across documents, tools, or standards that use different units.
Learn with Convr
Conversion guides
Metric vs Imperial Units: A Practical Comparison
Understand how metric, US customary, and Imperial units differ, where each system is used, and how to convert between them reliably.
Read guide →FoundationsSignificant Figures and Rounding in Unit Conversions
Learn when to round conversion results, how significant figures preserve measurement meaning, and why more decimals do not guarantee more accuracy.
Read guide →Answers at a glance
Frequently asked questions
How do you convert Carat to Stone?
Use the formula st = ct × 0.000031. Enter any value in the converter above to calculate the result instantly.
How many stone are in one carat?
One carat equals 0.000031 stone.
How does Convr round Carat to Stone results?
Convr keeps full numeric precision during the calculation and rounds only the displayed result. The default is a maximum of 6 decimal places, with selectable precision on this page.
Can I convert negative or decimal carat values?
Yes. The converter accepts positive, negative, decimal, and scientific-notation values. Negative values are physically meaningful for some scales, such as temperature, but not for every measured quantity.
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