Carat to Stone Conversion Calculator: Free Online Tool
Convert carats to stones with our free online weight converter.
Carat to Stone Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Carat).
- The converted value in Stone will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Weight category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Carat to Stone
Converting Carat to Stone involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Carat = 0.0000314946 stonesExample Calculation:
Convert 5 carats: 5 × 0.0000314946 = 0.000157473 stones
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Carat and a Stone?
The carat is a unit of mass used for measuring gemstones and pearls. It is defined as exactly 200 milligrams (0.2 grams).
The stone (st) is a unit of mass in the British imperial system, defined as exactly 14 avoirdupois pounds. This is equivalent to approximately 6.35 kilograms.
Note: The Carat is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Stone belongs to the imperial/US customary system.
History of the Carat and Stone
The term "carat" comes from the carob seed ("keration" in Greek), which was historically used as a standard for weighing small quantities due to its perceived uniform weight. The metric carat of 200 mg was adopted internationally in 1907.
The stone has historical roots in trade, where actual stones were used as weights. Its value varied significantly by commodity and region before being standardized at 14 pounds in Britain for general purposes.
Common Uses for carats and stones
Explore the typical applications for both Carat (imperial/US) and Stone (imperial/US) to understand their common contexts.
Common Uses for carats
- Jewelry Industry: The primary unit for weighing diamonds and other precious gemstones.
- Pearls: Used for weighing pearls.
- Note: This is distinct from "karat," which measures the purity of gold.
Common Uses for stones
- Body Weight: Primarily used in the UK and Ireland to express human body weight.
- Animal Weighing: Occasionally used informally for weighing large animals or agricultural produce in some Commonwealth countries.
- Historical Usage: Largely historical or colloquial use outside of body weight context.
Frequently Asked Questions
Questions About Carat (ct)
How many milligrams are in a carat?
There are exactly 200 milligrams (mg) in 1 carat (ct).
How many grams are in a carat?
There are 0.2 grams (g) in 1 carat (ct).
Is carat the same as karat?
No. Carat (ct) measures mass (weight) for gemstones, while Karat (K or kt) measures the purity of gold (e.g., 24K gold is pure gold).
About Stone (st)
How many pounds are in a stone?
There are 14 pounds (lb) in 1 stone (st).
Is the stone used outside the UK and Ireland?
Its use is very limited outside the UK and Ireland, mainly for historical context or by people familiar with imperial body weight measurements.
Why is it called a stone?
The name originates from the historical practice of using stones of a standardized size as weight standards in trade.
Conversion Table: Carat to Stone
| Carat (ct) | Stone (st) |
|---|---|
| 1 | 0 |
| 5 | 0 |
| 10 | 0 |
| 25 | 0.001 |
| 50 | 0.002 |
| 100 | 0.003 |
| 500 | 0.016 |
| 1,000 | 0.032 |
All Weight Conversions
Other Units from Weight
- Kilogram (kg)
- Gram (g)
- Milligram (mg)
- Pound (lb)
- Ounce (oz)
- Ton (metric) (t)
- Ton (US) (ton)
- Ton (UK) (long ton)
- Microgram (µg)
- Slug (sl)
- Troy Ounce (oz t)
- Pennyweight (dwt)
- Grain (gr)
- Dram (dr)
- Quintal (q)
- Atomic Mass Unit (u)
- Pavan (India) (pavan)
- Kati (India) (kati)
- Masha (India) (masha)
- Dina (India) (dina)
- Pras (India) (pras)
- Lota (India) (lota)