Carat to Grain Converter
Convert Carat (ct) to Grain (gr) instantly. 1 ct = 3.086472 gr.
Mass Converter
26 units available
1 ct = 3.086472 gr
Formula:
gr = ct × 3.0864716706With your value: 1 ct = 3.08647167 gr
How big is that?
Everyday references on a logarithmic scale, all expressed in carat so you can sanity-check the result.
Other Carat to Grain conversions
Carat to Grain Conversion Table
| Carat (ct) | Grain (gr) |
|---|---|
| 0.5 | 1.543236 |
| 1 | 3.086472 |
| 2 | 6.172943 |
| 5 | 15.432358 |
| 10 | 30.864717 |
| 15 | 46.297075 |
| 20 | 61.729433 |
| 25 | 77.161792 |
| 50 | 154.323584 |
| 100 | 308.647167 |
| 250 | 771.617918 |
| 500 | 1,543.235835 |
| 1000 | 3,086.471671 |
Grain to Carat Conversion Table
| Grain (gr) | Carat (ct) |
|---|---|
| 0.5 | 0.161997 |
| 1 | 0.323995 |
| 2 | 0.647989 |
| 5 | 1.619973 |
| 10 | 3.239945 |
| 15 | 4.859918 |
| 20 | 6.479891 |
| 25 | 8.099864 |
| 50 | 16.199727 |
| 100 | 32.399455 |
| 250 | 80.998638 |
| 500 | 161.997275 |
| 1000 | 323.99455 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Carat (ct)
Mass
The metric carat is exactly 200 mg, agreed internationally in 1907.
National Institute of Standards and Technology (US) · Reviewed 2026-07-01
Grain (gr)
Mass
Traceable to the kilogram, defined by fixing the Planck constant at 6.626 070 15 × 10⁻³⁴ J·s. Avoirdupois masses derive from the 1959 international pound (0.453 592 37 kg exactly).
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
How to Convert Carat to Grain
To convert from Carat (ct) to Grain (gr), multiply the value by 3.0864716706.
Formula: gr = ct × 3.0864716706
Reverse: ct = gr × 0.32399455
Step-by-Step Example
- Start with your value in Carat. For example: 5 ct
- Multiply by the conversion factor: 5 x 3.0864716706
- The result is: 15.432358 gr
About Carat
The carat equals 200 milligrams and is the standard unit for measuring gemstone weight.
Fun Fact: The word "carat" comes from the carob seed, which was used as a balance weight in ancient gem trading.
Common uses: gemstones, diamonds, jewelry.
About Grain
The grain equals exactly 64.79891 milligrams and was originally the weight of a single barleycorn. It is still the standard unit for bullets, propellant and arrows.
Common uses: ammunition, archery, pharmacy (historic).
Frequently Asked Questions
How many Grain are in 1 Carat?
There are exactly 3.0864716706 Grain in 1 Carat. This means the conversion factor from Carat to Grain is 3.0864716706.
What is the formula to convert Carat to Grain?
The formula to convert Carat to Grain is: gr = ct × 3.0864716706. For example, to convert 10 Carat to Grain, you would multiply 10 by 3.0864716706.
What is a Carat?
The carat equals 200 milligrams and is the standard unit for measuring gemstone weight.
What is a Grain?
The grain equals exactly 64.79891 milligrams and was originally the weight of a single barleycorn. It is still the standard unit for bullets, propellant and arrows.
What are the common uses of Carat?
The Carat is commonly used in gemstones, diamonds, jewelry.
Related Mass Conversions
Cite this page
UnitConvertLab. (2026). Carat to Grain converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/carat-to-grain