⚖️ oz to ct — Ounce to Carat Converter

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

1 unit =
From
To
Formula 1 oz = 141.7475 ct
Quick Answer — Formula1 oz = 141.7475 ctMultiply ounces by 141.7475 to get carats.Reverse: 1 ct = 0.007054798 oz
UnitNameValue
0.001 oz0.141747 ct
0.01 oz1.41747 ct
0.1 oz14.1747 ct
1 oz141.747 ct
5 oz708.737 ct
10 oz1417.47 ct
50 oz7087.37 ct
100 oz14174.7 ct
1000 oz141747 ct

About Ounce 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 oz = 141.7475 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: Ounce to Carat

A 1-carat diamond solitaire
1 oz = 141.7475 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 oz = 708.7375 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 oz = 141.7475 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 oz = 425.2425 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.

Ounce to Carat Reference Table

Ounce (oz)Carat (ct)Real-world context
0.1 oz14.17475 ct
1 oz141.7475 ctletter envelope
5 oz708.7375 ct
10 oz1417.475 ct
100 oz14174.75 ct

Mental Math Tricks: Ounce to Carat

Round factor trick
Round 141.7475 to 142 for quick mental math. Error ≈ 0.2%.
Break factor into parts
Split 141.7475 as 141 + 0.7475 for easier mental arithmetic.
Use ×{approx} then adjust
Multiply by 142 first, then − 0.25×n.

When to Convert Ounce to Carat

💎 Jewellery Design Jewellers specify gemstone weights in carats and metal weights in grams or tola. Converting oz to ct is a core skill in jewellery making.
🏆 Gemstone Grading The 4Cs of diamond grading include carat weight. Converting between oz 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. Ounce to Carat conversion is essential for traders and investors.
⚖️ Hallmarking Precious metal hallmarking authorities certify weights in specific units. Convert between oz 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 oz. Converting to modern ct helps calculate material value accurately.

Frequently Asked Questions — Ounce to Carat

1 ounce (oz) equals exactly 141.7475 carats (ct). Use the formula: oz × 141.7475 = ct.

To convert ounces to carats, multiply your value in ounces by 141.7475. For example, 5 oz × 141.7475 = 708.7375 ct.

100 ounces = 14174.75 carats. Calculation: 100 × 141.7475 = 14174.75.

To convert carats back to ounces, divide by 141.7475 (or multiply by 0.0070548). Example: 10 ct ÷ 141.7475 = 0.07054798 oz.

Yes. This converter uses the internationally recognised exact conversion factor: 1 oz = 141.7475 ct. All calculations are performed in your browser with no rounding until display.

10 ounces = 1417.475 carats. Simply multiply by 141.7475.

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

Understanding Ounce and Carat

Ounce (oz)

The avoirdupois ounce (oz) equals exactly 28.349523125 grams or 1/16 of an avoirdupois pound. It is widely used in the US and UK for food portions, product packaging, and everyday measurements. Note that the troy ounce (31.1035 g), used for precious metals like gold and silver, is a different and heavier unit than the avoirdupois ounce.

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 Ounce

The word "ounce" derives from Latin uncia (a twelfth), originally 1/12 of the Roman pound. The avoirdupois ounce developed in medieval England specifically for the wool trade, creating a 16-ounce pound distinct from the Troy 12-ounce pound. The British Imperial system codified the ounce in 1824. The modern exact definition (28.349523125 g) was set by the 1959 International Yard and Pound Agreement.

Interesting fact: A troy ounce (31.1 g) used for gold is heavier than an avoirdupois ounce (28.35 g) used for food — so an "ounce" of gold contains more metal than an "ounce" of flour. A standard large hen's egg weighs approximately 56–63 grams (about 2 oz).

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.