How to Convert Carats to Tonnes (ct to t)
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 tonnes by hand, with examples and a quick-reference table.
The conversion
To convert carats to tonnes, multiply the value by 2.000000e-07. To go the other way, divide by the same number (or multiply by 5,000,000). Because the factor is tiny, scientific notation keeps the numbers manageable.
Tonnes = carats × 2.000000e-07
Worked examples
- 3 ct = 6.000000e-7 t
- 12.5 ct = 2.500000e-6 t
- 75 ct = 1.500000e-5 t
Carats to Tonnes table
| Carats | Tonnes |
|---|---|
| 1 ct | 2.000000e-7 t |
| 2 ct | 4.000000e-7 t |
| 5 ct | 1.000000e-6 t |
| 10 ct | 2.000000e-6 t |
| 20 ct | 4.000000e-6 t |
| 25 ct | 5.000000e-6 t |
| 50 ct | 1.000000e-5 t |
| 100 ct | 2.000000e-5 t |
| 250 ct | 5.000000e-5 t |
| 500 ct | 0.0001 t |
| 1,000 ct | 0.0002 t |
Common questions
Is ct to t 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 Tonnes to Carats converter.
Mistakes to avoid
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.
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.
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Background
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.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
For any value, use the Carats to Tonnes Converter or browse all weight converters.
Run your own numbers: Carats to Tonnes Converter