How to Convert Carats to Milligrams (ct to mg)
Weight units matter at the wet market, where older stalls and Chinese medical halls still quote prices per kati or tael, and when following American recipes in ounces and pounds. This guide shows how to convert carats into milligrams by hand, with examples and a quick-reference table.
The conversion
To convert carats to milligrams, multiply the value by 200. To go the other way, divide by the same number (or multiply by 0.005). For a quick estimate, multiply by about 200.
Milligrams = carats × 200
Worked examples
- 3 ct = 600 mg
- 12.5 ct = 2,500 mg
- 75 ct = 15,000 mg
Carats to Milligrams table
| Carats | Milligrams |
|---|---|
| 1 ct | 200 mg |
| 2 ct | 400 mg |
| 5 ct | 1,000 mg |
| 10 ct | 2,000 mg |
| 20 ct | 4,000 mg |
| 25 ct | 5,000 mg |
| 50 ct | 10,000 mg |
| 100 ct | 20,000 mg |
| 250 ct | 50,000 mg |
| 500 ct | 100,000 mg |
| 1,000 ct | 200,000 mg |
Common questions
Is ct to mg exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Milligrams to Carats converter.
Mistakes to avoid
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Multiplying when you should divide
Converting to a smaller unit gives a bigger number, and converting to a larger unit gives a smaller one. If your answer moves the wrong way, you have inverted the factor.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Background
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
For any value, use the Carats to Milligrams Converter or browse all weight converters.
Run your own numbers: Carats to Milligrams Converter