Grain to Carat Conversion Calculator: Free Online Tool
Convert grains to carats with our free online weight converter.
Grain to Carat Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Grain).
- The converted value in Carat will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Weight category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Grain to Carat
Converting Grain to Carat involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Grain = 0.323995 caratsExample Calculation:
Convert 5 grains: 5 × 0.323995 = 1.61997 carats
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 Grain and a Carat?
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).
The carat is a unit of mass used for measuring gemstones and pearls. It is defined as exactly 200 milligrams (0.2 grams).
Note: The Grain is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Carat belongs to the imperial/US customary system.
History of the Grain and Carat
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.
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.
Common Uses for grains and carats
Explore the typical applications for both Grain (imperial/US) and Carat (imperial/US) to understand their common contexts.
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.
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.
Frequently Asked Questions
Questions 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).
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).
Conversion Table: Grain to Carat
| Grain (gr) | Carat (ct) |
|---|---|
| 1 | 0.324 |
| 5 | 1.62 |
| 10 | 3.24 |
| 25 | 8.1 |
| 50 | 16.2 |
| 100 | 32.4 |
| 500 | 161.997 |
| 1,000 | 323.995 |
All Weight Conversions
Other Units from Weight
- Kilogram (kg)
- Gram (g)
- Milligram (mg)
- Pound (lb)
- Ounce (oz)
- Stone (st)
- Ton (metric) (t)
- Ton (US) (ton)
- Ton (UK) (long ton)
- Microgram (µg)
- Slug (sl)
- Troy Ounce (oz t)
- Pennyweight (dwt)
- Dram (dr)
- Quintal (q)
- Atomic Mass Unit (u)
- Pavan (India) (pavan)
- Kati (India) (kati)
- Masha (India) (masha)
- Dina (India) (dina)
- Pras (India) (pras)
- Lota (India) (lota)