Convert Carat to Metric Ton (ct → t)
The carat equals 200 milligrams exactly and is the universal unit for gemstone and diamond weight in jewelry.
Carat to Metric Ton Conversion Table
10 common values| Carat | Metric Ton |
|---|---|
| 1 ct | 2e-7 t |
| 5 ct | 0.000001 t |
| 10 ct | 0.000002 t |
| 25 ct | 0.000005 t |
| 50 ct | 0.00001 t |
| 100 ct | 0.00002 t |
| 250 ct | 0.00005 t |
| 500 ct | 0.0001 t |
| 1,000 ct | 0.0002 t |
| 5,000 ct | 0.001 t |
How to Convert Carat to Metric Ton Manually
Step by StepConverting carats to metric tons is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in caratsStart with the number of carats (ct) you want to convert.
- 2Multiply by 2e-7The conversion factor from ct to t is 2e-7. Multiply your value by this number.
- 3Read the result in metric tonsThe result is your value in metric tons (t).
Formula
Multiply the value in carats by 2e-7. For the reverse direction, multiply by 5,000,000.
t = ct × 2e-7ct = t × 5,000,000Tips
Use these in everyday conversions- 1 carat = 200 mg = 0.2 g exactly since 1907.
- Carat (gem weight) and karat (gold purity, 24 K = pure) are different words with different meanings.
- A carat is divided into 100 points; a 0.25 ct diamond is called a "25-pointer".
Common Mistakes
Avoid these- Confusing carat (mass) with karat (gold purity).
- Assuming a 2-carat diamond is twice the physical size of a 1-carat — volume scales with cube root of mass.
- Using "karat" on gemstone certificates — international standard is "carat" spelled with a C.
About Carat and Metric Ton
What is the Carat?
The carat equals exactly 200 milligrams (0.2 g) and is the universal unit for gemstone and diamond weight in the global jewelry industry. The word derives from the Greek 'keration' and the Arabic 'qīrāṭ,' both referring to carob seeds, which were once used as natural counterweights for weighing gems because they have remarkably uniform mass. The metric carat was standardized in 1907 at exactly 200 mg, replacing dozens of regional carat values that had varied between 188 and 213 mg. A 1-carat diamond is roughly 6.5 mm in diameter, and the famous Hope Diamond weighs 45.52 carats. The carat is distinct from the karat (with a 'k'), which measures gold purity (24-karat = 100% gold). It relates to the gram (5 ct = 1 g) and the milligram (200 mg = 1 ct). Gem dealers commonly use 'points' for fractions (100 points = 1 carat).
- Diamond and gemstone retail and valuation
- Jewellery manufacturing and design
- International gem certification (GIA, IGI)
A 1-carat diamond weighs 200 mg and is typically 6.5 mm across. The Hope Diamond is 45.52 carats (9.1 g).
What is the Metric Ton?
The metric ton (or tonne) equals exactly 1,000 kilograms and is the international standard for shipping, agriculture, construction, and industrial weight. Adopted as part of the SI system, the metric ton is used worldwide for bulk commodities (grain harvests measured in tons per hectare), vehicle and shipping container masses, freight rates, and CO₂ emissions accounting. A standard 20-foot shipping container has a maximum gross weight of about 24 metric tons. The metric ton is distinct from the US short ton (907.185 kg) and the UK long ton (1,016.047 kg). The unit's spelling differs by country — 'tonne' in British and international usage, 'metric ton' in American — but the abbreviation 't' is universal. It relates to the kilogram (1,000 kg = 1 t) and the megagram (1 Mg = 1 t).
- International shipping and freight
- Agricultural yield (grain, sugar, coffee)
- Steel, cement and industrial production
A mid-size car weighs about 1.5 t. A 20-ft shipping container holds up to 28 t. Global steel output is about 1,900 million tonnes per year.