⚖️ st to ct — Stone to Carat Converter

Convert weight and mass units — kilograms, pounds, grams, ounces, tons, carats and more.

1 unit =
From
To
Formula 1 st = 31751.45 ct
Quick Answer — Formula1 st = 31751.45 ctMultiply stones by 31751.45 to get carats.Reverse: 1 ct = 0.00003149462 st
UnitNameValue
0.001 st31.7514 ct
0.01 st317.514 ct
0.1 st3175.14 ct
1 st31751.4 ct
5 st158757 ct
10 st317514 ct
50 st1.58757e+06 ct
100 st3.17514e+06 ct
1000 st3.17514e+07 ct

About Stone to Carat Conversion

The Milligram (mg) and the Gram (g) are both units of weight & mass. Converting between them is straightforward using the formula above.

Formula: 1 st = 31751.45 ct

This converter uses internationally recognized conversion factors. All calculations are performed client-side in your browser — no data is sent to any server.

Worked Examples: Stone to Carat

A 1-carat diamond solitaire
1 st = 31751.45 ct
The classic engagement ring stone is a 1-carat diamond = 0.2 g. Jewellers worldwide quote gemstone weight in carats and fractions of carats.
A large gemstone
5 st = 158757.25 ct
A 5-carat ruby is considered a fine specimen — it weighs just 1 gram, showing how small even prestigious gemstones truly are.
A tola of gold bar
1 st = 31751.45 ct
A 1-tola gold bar (≈11.66 g) is the most common retail gold investment unit across India, Pakistan, and UAE.
A gem-quality sapphire
3 st = 95254.35 ct
A 3-carat blue sapphire weighs 0.6 g. The per-carat price of fine sapphires can exceed $10,000, so precise weight measurement is critical.

Stone to Carat Reference Table

Stone (st)Carat (ct)Real-world context
0.001 st31.75145 ct
0.01 st317.5145 ct
0.1 st3175.145 ct
1 st31751.45 ct
10 st317514.5 ct

Mental Math Tricks: Stone to Carat

Round to nearest hundred
For quick estimates, use 31800 instead of 31751.45. Error ≤ 0.2%.
Scientific notation
1 st = 3.18e+04 ct. Move the decimal point accordingly.
Work in thousands
Every 1000 stone = 31,751,450 ct.

When to Convert Stone to Carat

💎 Jewellery Design Jewellers specify gemstone weights in carats and metal weights in grams or tola. Converting st to ct is a core skill in jewellery making.
🏆 Gemstone Grading The 4Cs of diamond grading include carat weight. Converting between st and ct helps compare stones across different grading systems.
💰 Gold Trading Gold prices are quoted per gram, per tola, and per troy ounce depending on the market. Stone to Carat conversion is essential for traders and investors.
⚖️ Hallmarking Precious metal hallmarking authorities certify weights in specific units. Convert between st and ct for compliance and documentation.
🎯 Archery & Ballistics Arrow and bullet weights are specified in grains. Converting to grams or vice versa is routine for archers and competitive shooters.
🏛️ Antique Appraisal Historical weights for silver and gold artefacts may be recorded in st. Converting to modern ct helps calculate material value accurately.

Frequently Asked Questions — Stone to Carat

1 stone (st) equals exactly 31751.45 carats (ct). Use the formula: st × 31751.45 = ct.

To convert stone to carats, multiply your value in stone by 31751.45. For example, 5 st × 31751.45 = 158757.25 ct.

100 stone = 3,175,145 carats. Calculation: 100 × 31751.45 = 3,175,145.

To convert carats back to stone, divide by 31751.45 (or multiply by 3.1495e-05). Example: 10 ct ÷ 31751.45 = 0.00031495 st.

Yes. This converter uses the internationally recognised exact conversion factor: 1 st = 31751.45 ct. All calculations are performed in your browser with no rounding until display.

10 stone = 317514.5 carats. Simply multiply by 31751.45.

Converting stone to carats is commonly needed for jewellery valuation, gemstone trading, precious metal buying and selling, and hallmarking compliance where one system uses st and another uses ct.

Understanding Stone and Carat

Stone (st)

The stone (st) is a British imperial unit of mass equal to exactly 14 avoirdupois pounds or 6.35029318 kilograms. Used almost exclusively in the United Kingdom and Ireland for human body weight, it has no role in scientific, commercial, or international contexts. The stone is not an SI unit and was removed from official UK trade measurement in 1985, though it remains deeply embedded in everyday British culture.

Carat (ct)

The metric carat (ct) is the unit of mass used worldwide for gemstones and pearls, equal to exactly 200 milligrams (0.2 g). It is distinct from "karat" (K), the measure of gold purity (24K = 100% gold). A 1-carat diamond weighs exactly 0.2 g; the famous 45.52-carat Hope Diamond weighs approximately 9.1 g.

History of the Stone

One of the oldest English weight units, the stone was referenced as early as the 13th century. Historically its value varied by commodity (8 lb for meat, 12 lb for hemp, 14 lb for wool, 16 lb for glass). King Edward III standardised the wool stone at 14 pounds in 1350, which became the universal English standard. The Weights and Measures Act 1835 formally defined the stone as 14 lb. EU harmonisation abolished the stone for trade in 1985.

Interesting fact: The world record heaviest person weighed 635 kg — exactly 100 stone, illustrating how the stone unit provides digestible reference points for large body weights. British people typically express their weight as, for example, "11 stone 4 pounds."

History of the Carat

The word "carat" derives from Greek keration (κεράτιον), meaning carob pod. Carob seeds were believed to have remarkably uniform weight and were used as counterweights for balancing precious stones. The carat value varied across countries (0.187–0.216 g) until the Fourth General Conference on Weights and Measures standardised the metric carat at exactly 200 mg in 1907. Most countries adopted the metric carat between 1914 and 1930.

Interesting fact: The largest gem-quality diamond ever found, the Cullinan Diamond (1905), weighed 3,106.75 carats (621.35 g) before being cut into 9 major and 96 minor stones, two of which are in the British Crown Jewels.