Grain to Milligram Conversion Calculator: Free Online Tool
Convert grains to milligrams with our free online weight converter.
Grain to Milligram Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Grain).
- The converted value in Milligram 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 Milligram
Converting Grain to Milligram involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Grain = 64.7989 milligramsExample Calculation:
Convert 5 grains: 5 × 64.7989 = 323.995 milligrams
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 Milligram?
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 milligram is a unit of mass in the metric system equal to one-thousandth of a gram (1/1000 g) or one-millionth of a kilogram (1/1,000,000 kg). It is commonly used for measuring very small quantities.
Note: The Grain is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Milligram belongs to the metric (SI) system.
History of the Grain and Milligram
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.
Like the gram, the milligram's definition is derived directly from the kilogram. Its use became prevalent with the need for precise measurements in science and medicine as the metric system was adopted globally.
Common Uses for grains and milligrams
Explore the typical applications for both Grain (imperial/US) and Milligram (metric) 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 milligrams
- Pharmaceuticals: Measuring the dosage of medications, pills, and active ingredients in drugs.
- Scientific Research: Common unit for mass measurements in chemistry labs, biology, and physics experiments for very small quantities.
- Nutrition & Supplements: Used for labeling the content of vitamins, minerals, and other nutrients in dietary supplements.
- Precision Manufacturing: Weighing very lightweight items like microelectronic components, fine powders, or precious materials.
- Analytical Chemistry: Standard unit for quantifying trace elements and compounds in samples.
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 Milligram (mg)
How many milligrams are in a gram?
There are 1,000 milligrams (mg) in 1 gram (g).
Is the milligram used in everyday life?
Its most common everyday use is in medication dosages and supplement information. It's less common for general weighing compared to grams or kilograms.
What does 'milli' mean in milligram?
The prefix 'milli' denotes one-thousandth (1/1000).
Conversion Table: Grain to Milligram
| Grain (gr) | Milligram (mg) |
|---|---|
| 1 | 64.799 |
| 5 | 323.995 |
| 10 | 647.989 |
| 25 | 1,619.973 |
| 50 | 3,239.946 |
| 100 | 6,479.891 |
| 500 | 32,399.455 |
| 1,000 | 64,798.91 |
All Weight Conversions
Other Units from Weight
- Kilogram (kg)
- Gram (g)
- Pound (lb)
- Ounce (oz)
- Stone (st)
- Ton (metric) (t)
- Ton (US) (ton)
- Ton (UK) (long ton)
- Microgram (µg)
- Carat (ct)
- 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)