Carat to Grain Conversion Calculator: Free Online Tool

Convert carats to grains with our free online weight converter.

Carat to Grain Calculator

Carat
Grain

How to Use the Calculator:

  1. Enter the value you want to convert in the 'From' field (Carat).
  2. The converted value in Grain will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Weight category.
  4. Click the swap button (⇌) to reverse the conversion direction.

How to Convert Carat to Grain

Converting Carat to Grain involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Carat = 3.08647 grains

Example Calculation:

Convert 5 carats: 5 × 3.08647 = 15.4323 grains

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Carat and a Grain?

The carat is a unit of mass used for measuring gemstones and pearls. It is defined as exactly 200 milligrams (0.2 grams).

The grain (gr) is a unit of mass in the traditional English weight systems (Avoirdupois, Troy, and Apothecaries'). It was originally based on the weight of a single grain of barley. It is defined as exactly 64.79891 milligrams (or 1/7000 of an avoirdupois pound).

Note: The Carat is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Grain belongs to the imperial/US customary system.

History of the Carat and Grain

The term "carat" comes from the carob seed ("keration" in Greek), which was historically used as a standard for weighing small quantities due to its perceived uniform weight. The metric carat of 200 mg was adopted internationally in 1907.

The grain is one of the oldest units of mass, dating back to antiquity, using seeds (like barley or wheat) as weight standards. It formed the legal basis for English weight systems and remains defined in terms of metric units today.

Common Uses for carats and grains

Explore the typical applications for both Carat (imperial/US) and Grain (imperial/US) to understand their common contexts.

Common Uses for carats

  • Jewelry Industry: The primary unit for weighing diamonds and other precious gemstones.
  • Pearls: Used for weighing pearls.
  • Note: This is distinct from "karat," which measures the purity of gold.

Common Uses for grains

  • Ammunition: Measuring the mass of bullets and gunpowder charges.
  • Archery: Measuring the mass of arrows and arrowheads.
  • Medicine & Pharmacy: Historically used in the apothecaries' system; sometimes still used for measuring dosage of certain older medications (e.g., aspirin).
  • Jewelry: Used in the troy system (24 grains = 1 pennyweight).
  • Reloading: Handloading ammunition requires precise measurement in grains.

Frequently Asked Questions

Questions About Carat (ct)

How many milligrams are in a carat?

There are exactly 200 milligrams (mg) in 1 carat (ct).

How many grams are in a carat?

There are 0.2 grams (g) in 1 carat (ct).

Is carat the same as karat?

No. Carat (ct) measures mass (weight) for gemstones, while Karat (K or kt) measures the purity of gold (e.g., 24K gold is pure gold).

About Grain (gr)

How many grains are in an ounce (avoirdupois)?

There are 437.5 grains (gr) in 1 avoirdupois ounce (oz).

How many grains are in a pound (avoirdupois)?

There are 7,000 grains (gr) in 1 avoirdupois pound (lb).

How many milligrams are in a grain?

There are exactly 64.79891 milligrams (mg) in 1 grain (gr).

Conversion Table: Carat to Grain

Carat (ct)Grain (gr)
13.087
515.432
1030.865
2577.162
50154.324
100308.647
5001,543.236
1,0003,086.472

All Weight Conversions

Kilogram to GramKilogram to MilligramKilogram to PoundKilogram to OunceKilogram to StoneKilogram to Ton (metric)Kilogram to Ton (US)Kilogram to Ton (UK)Kilogram to MicrogramKilogram to CaratKilogram to SlugKilogram to Troy OunceKilogram to PennyweightKilogram to GrainKilogram to DramKilogram to QuintalKilogram to Atomic Mass UnitKilogram to Pavan (India)Kilogram to Kati (India)Kilogram to Masha (India)Kilogram to Dina (India)Kilogram to Pras (India)Kilogram to Lota (India)Gram to KilogramGram to MilligramGram to PoundGram to OunceGram to StoneGram to Ton (metric)Gram to Ton (US)Gram to Ton (UK)Gram to MicrogramGram to CaratGram to SlugGram to Troy OunceGram to PennyweightGram to GrainGram to DramGram to QuintalGram to Atomic Mass UnitGram to Pavan (India)Gram to Kati (India)Gram to Masha (India)Gram to Dina (India)Gram to Pras (India)Gram to Lota (India)Milligram to KilogramMilligram to GramMilligram to PoundMilligram to OunceMilligram to StoneMilligram to Ton (metric)Milligram to Ton (US)Milligram to Ton (UK)Milligram to MicrogramMilligram to CaratMilligram to SlugMilligram to Troy OunceMilligram to PennyweightMilligram to GrainMilligram to DramMilligram to QuintalMilligram to Atomic Mass UnitMilligram to Pavan (India)Milligram to Kati (India)Milligram to Masha (India)Milligram to Dina (India)Milligram to Pras (India)Milligram to Lota (India)Pound to KilogramPound to GramPound to MilligramPound to OuncePound to StonePound to Ton (metric)Pound to Ton (US)Pound to Ton (UK)Pound to MicrogramPound to CaratPound to SlugPound to Troy OuncePound to PennyweightPound to GrainPound to DramPound to QuintalPound to Atomic Mass UnitPound to Pavan (India)Pound to Kati (India)Pound to Masha (India)Pound to Dina (India)Pound to Pras (India)Pound to Lota (India)Ounce to KilogramOunce to GramOunce to MilligramOunce to PoundOunce to StoneOunce to Ton (metric)Ounce to Ton (US)Ounce to Ton (UK)Ounce to MicrogramOunce to CaratOunce to SlugOunce to Troy OunceOunce to PennyweightOunce to GrainOunce to DramOunce to QuintalOunce to Atomic Mass UnitOunce to Pavan (India)Ounce to Kati (India)Ounce to Masha (India)Ounce to Dina (India)Ounce to Pras (India)Ounce to Lota (India)Stone to KilogramStone to GramStone to MilligramStone to PoundStone to Ounce