Mass Measurement & Unit Converter
Precise weight measurement is essential for gemstone valuation and identification. Convert between carats, grams, milligrams, and ounces with our easy-to-use tools.
Interactive Weight Converter
⚖️ 1 Carat = 0.2 Grams = 200 Milligrams = 0.007055 Ounces
Carats
ct
Grams:
0.200
Milligrams:
200.0
Ounces:
0.0071
Grams
g
Carats:
1.00
Milligrams:
200.0
Ounces:
0.0071
Milligrams
mg
Carats:
1.00
Grams:
0.200
Ounces:
0.0071
Ounces
oz
Carats:
1.00
Grams:
0.200
Milligrams:
200.0
Typical Gemstone Weights
Precious Stones
- 💎 Diamond 0.5 - 3 ct
- ❤️ Ruby 0.5 - 5 ct
- 💙 Sapphire 0.5 - 10 ct
- 💚 Emerald 0.3 - 5 ct
Semi-Precious
- 💜 Amethyst 1 - 20 ct
- 💛 Topaz 1 - 30 ct
- 💚 Peridot 1 - 15 ct
- 🌈 Tourmaline 1 - 25 ct
Organic Gems
- 🐚 Pearl 2 - 20 ct
- 🌈 Opal 1 - 30 ct
- 🪸 Coral 5 - 50 ct
- 🦑 Amber 5 - 100 ct
Investment Grade
- 💎 Fine Diamond 1+ ct
- ❤️ Burma Ruby 2+ ct
- 💙 Kashmir Sapphire 3+ ct
- 💚 Colombian Emerald 2+ ct
Carat to Size Comparison
| Carat Weight | Diamond (mm) | Ruby/Sapphire (mm) | Emerald (mm) |
|---|---|---|---|
| 0.25 ct | 4.0 mm | 3.8 mm | 4.2 mm |
| 0.50 ct | 5.0 mm | 4.8 mm | 5.3 mm |
| 1.00 ct | 6.5 mm | 6.0 mm | 6.8 mm |
| 1.50 ct | 7.4 mm | 6.9 mm | 7.8 mm |
| 2.00 ct | 8.2 mm | 7.6 mm | 8.6 mm |
| 3.00 ct | 9.4 mm | 8.7 mm | 9.9 mm |
| 5.00 ct | 11.0 mm | 10.3 mm | 11.7 mm |
Conversion Formulas
Carat Conversions
- 1 carat = 0.2 grams
- 1 carat = 200 milligrams
- 1 carat = 0.007055 ounces
- 5 carats = 1 gram
Gram Conversions
- 1 gram = 5 carats
- 1 gram = 1000 milligrams
- 1 gram = 0.035274 ounces
- 28.35 grams = 1 ounce
Milligram Conversions
- 100 mg = 0.5 carats
- 200 mg = 1 carat
- 1000 mg = 5 carats
- 1000 mg = 1 gram
Ounce Conversions
- 1 oz = 141.75 carats
- 1 oz = 28.35 grams
- 1 oz = 28,350 milligrams
- 0.1 oz = 14.2 carats
Frequently Asked Questions
Why are gemstones measured in carats?
The carat system dates back to ancient times when gemstones were weighed against carob seeds, which were believed to have uniform weight. Today, 1 carat is standardized to exactly 0.2 grams.
How accurate does my scale need to be?
For professional gemstone trading, scales should be accurate to 0.001g (0.005 carats). For hobbyists, 0.01g accuracy is usually sufficient. Our converter works with any precision scale.
Do different gemstones weigh the same per carat?
Yes! A carat is a unit of weight, so 1 carat of diamond weighs the same as 1 carat of ruby. However, due to different densities, they may appear different sizes - diamonds appear larger because they're less dense.
What's the difference between carat and karat?
"Carat" (ct) refers to gemstone weight. "Karat" (K) refers to gold purity (24K is pure gold). They're often confused but measure completely different properties.
How does weight affect gemstone value?
Gemstone prices increase exponentially with weight. A 2-carat diamond typically costs 3-4 times more than a 1-carat of similar quality. This is why precise weight measurement is crucial for valuation.
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