How many carats are in one metric tonne?

There are exactly 5,000,000 carats in one metric tonne. This is because 1 carat = 0.2 g and 1 tonne = 1,000,000 g, so 1,000,000 ÷ 0.2 = 5,000,000.

Is a carat the same as a karat?

No. A carat (ct) is a unit of mass (0.2 grams) used for gemstones. A karat (kt) is a measure of gold purity (24 kt = pure gold). They are unrelated units.

What is a metric tonne?

A metric tonne (t) equals 1,000 kilograms or 1,000,000 grams. It is different from the US short ton (907 kg) and the British long ton (1,016 kg).

Can I convert fractions of a tonne?

Yes. Enter any decimal value such as 0.001 (1 kilogram) and the converter will calculate the precise carat equivalent.

Why are gemstones weighed in carats?

The carat originated from the carob seed, which was used as a balance weight by ancient traders due to its relatively uniform mass. The unit was standardized internationally in 1907 at 0.2 grams.

Tonnes to Carats Converter

Enter a weight in metric tonnes and instantly get the equivalent in carats (1 t = 5,000,000 ct).

Tonnes → Carats

1 t = 5,000,000 ct

Metric Tonnes (t) Result in Carats (ct)

Carats → Tonnes

1 ct = 0.0000002 t

Carats (ct) Result in Tonnes (t)

Common Conversion Reference

Metric Tonnes (t)	Carats (ct)	Grams (g)
0.000 000 2	1	0.2
0.000 001	5	1
0.001	5,000	1,000
0.01	50,000	10,000
0.1	500,000	100,000
1	5,000,000	1,000,000

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Summary

The carat (ct) is the standard unit of mass used for gemstones and pearls, where 1 carat equals exactly 0.2 grams. A metric tonne equals 1,000,000 grams, so 1 tonne contains 5,000,000 carats. This converter handles any quantity — from tiny fractions of a tonne to large industrial amounts — and also shows the reverse conversion from carats back to tonnes.

How it works

Enter the weight in metric tonnes in the input field.
The tool multiplies your value by 5,000,000 (the number of carats per tonne).
The result in carats is displayed instantly.
Use the reverse field to convert carats back to tonnes.
Click Copy to copy either result to your clipboard.

Use cases

Convert gem rough material weights for bulk trading.
Cross-check carat totals when reviewing mining output reports.
Education: understand the scale between everyday mass and gemstone weight.
Jewelry industry: compare large lot weights expressed in tonnes to per-stone carat counts.
Scientific research involving diamond or corundum specimens.
Customs and import paperwork requiring carat declarations.

Frequently Asked Questions

Last updated: 2026-06-04 · Reviewed by Nham Vu