Carat to Stone Converter
Convert carats to stones instantly. Free, bidirectional, and fully in-browser.
About this tool
Carat to Stone Converter
Convert carats to stones instantly. Free, bidirectional, and fully in-browser.
1 carat equals 3.149461e-5 stones — enter any carat value to convert it to stones instantly. This Carat to Stone converter is a client-side tool: it applies a single multiplication (st = ct × 3.149461e-5) in your browser, updates the moment you type, and works in both directions — edit either field, or press swap, to convert stones back to carats. A reference table lists common carat values already converted, and nothing you enter is sent to a server.
How to use Carat to Stone Converter
- 1
Open Carat to Stone Converter on AltFTool — it loads instantly in your browser.
- 2
Type the value you want to convert into the Carat field.
- 3
Read the equivalent in stones in the result field, and copy it if needed.
- 4
Use the decimal-places slider for more or less precision, or press swap to convert stones to carats.
Why use Carat to Stone Converter
Instant, both ways
The result updates as you type, and the swap button flips the conversion to stone → carat without reloading.
Exact Mass math
The conversion uses the precise factor (st = ct × 3.149461e-5), so the number matches a manual calculation to the decimal places you choose.
Adjustable precision
A slider sets 0–10 decimal places, and very small or very large results switch to scientific notation instead of rounding to zero.
Private and free
Everything runs locally in your browser — no upload, no account, no limit on conversions.
Common use cases
- Converting a carat measurement to stones for a spec, listing, or report.
- Checking carat↔stone figures while comparing products, datasets, or documentation.
- Learning the carat-to-stone relationship from the worked formula and the common-value table.
Frequently asked questions
How many stones are in a carat?
One carat is 3.149461e-5 stones. Multiply the carat value by 3.149461e-5 to convert. For example, 10 ct = 0.0003149460888 st.
What is the formula to convert carats to stones?
st = ct × 3.149461e-5. This tool applies it automatically and shows a worked example: 10 ct = 0.0003149460888 st.
Can it convert stones back to carats?
Yes. Press the swap button, or type into the stone field, and the tool converts stones to carats using the inverse of the same relationship.
Is the conversion accurate?
It uses the standard mass and weight definition (st = ct × 3.149461e-5), not a rounded approximation, so results are exact to the number of decimal places you select.
Does this work offline and stay private?
Yes. The converter is a browser-side script with no network calls: your values are never uploaded, and once the page has loaded it keeps working without a connection.
Embed this tool on your site
Add the Carat to Stone Converter widget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
<iframe src="https://www.altftool.com/embed/widget/carats-to-stones-converter"
title="Carat to Stone Converter — free AltFTool widget"
width="100%" height="640" style="border:0;border-radius:12px;overflow:hidden"
loading="lazy" referrerpolicy="no-referrer-when-downgrade" allow="clipboard-write"></iframe>
<p style="font-size:12px;margin:4px 0 0">Widget by <a href="https://www.altftool.com/tools/all/carats-to-stones-converter?utm_source=embed&utm_medium=widget" rel="nofollow">AltFTool — free online tools</a></p>