Grains to Grams Calculator
Convert between grains (gr) and grams (g) instantly. Perfect for ammunition reloading, jewelry, pharmacy, and precise weight measurements. Enter a value in either unit to get the equivalent weight.
What Is a Grain (gr)?
A grain (gr) is a unit of mass that has been used since antiquity. It is defined as exactly 0.06479891 grams (64.79891 milligrams). The grain is the smallest unit in the avoirdupois, troy, and apothecaries' weight systems, and it is still commonly used today in ammunition reloading, jewelry making, and pharmacy.
A gram (g) is the base unit of mass in the metric system and is widely used around the world for everyday measurements. One gram is equal to approximately 15.43235835 grains.
How Does the Grains to Grams Calculator Work?
The calculator uses the exact conversion factors:
1 gr = 0.06479891 g
1 g = 15.43235835 gr
These conversion factors are exact and defined by the international yard and pound agreement of 1959. The grain is defined as exactly 1/7000 of the avoirdupois pound, and the gram is defined in terms of the kilogram.
Simply enter a value in either grains or grams, select the direction of conversion, and the calculator will instantly compute the equivalent weight.
Why Use This Grains to Grams Calculator?
- Two-Way Conversion: Convert from grains to grams and from grams to grains.
- Precise Results: Uses the exact conversion factor (0.06479891).
- Scientific Notation: Display very small or large numbers in scientific format.
- Reference Table: Quick reference for common weight values.
- Free & Private: No registration, no data storage.
Common Grain Equivalents
- 1 gr = 0.06479891 g = 64.79891 mg
- 10 gr ≈ 0.648 g
- 100 gr ≈ 6.480 g
- 7000 gr = 1 lb (avoirdupois) = 453.59237 g
- 5760 gr = 1 troy lb = 373.2417216 g
- 437.5 gr = 1 oz (avoirdupois) = 28.349523125 g
- 480 gr = 1 oz (troy) = 31.1034768 g
❓ Grains to Grams Calculator FAQ
What is a grain (gr)?
A grain is a unit of mass equal to exactly 0.06479891 grams (64.79891 mg). It is the smallest unit in the avoirdupois, troy, and apothecaries' weight systems.
What is a gram (g)?
A gram is the base unit of mass in the metric system. One gram is approximately equal to 15.43235835 grains.
How many grams are in a grain?
1 grain (gr) = 0.06479891 grams (g).
How many grains are in a gram?
1 gram (g) = 15.43235835 grains (gr).
What is the formula for converting grains to grams?
g = gr × 0.06479891. For example, 100 gr × 0.06479891 = 6.479891 g.
What is the formula for converting grams to grains?
gr = g × 15.43235835. For example, 10 g × 15.43235835 = 154.3235835 gr.
What is a grain used for?
Grains are commonly used for measuring ammunition (bullet weight, powder charges), jewelry (precious metals), and pharmacy (medication dosages).
How many grains are in a pound?
There are 7000 grains in one avoirdupois pound (lb).
How many grains are in an ounce?
There are 437.5 grains in one avoirdupois ounce (oz) and 480 grains in one troy ounce (oz t).
What is the difference between avoirdupois and troy grains?
The grain is the same in both systems — 1 grain = 0.06479891 grams. The difference is in how many grains make up larger units: 7000 grains per avoirdupois pound vs. 5760 grains per troy pound.
How do I convert grains to milligrams?
1 grain = 64.79891 mg. Multiply grains by 64.79891 to get milligrams.
How do I convert grams to milligrams?
1 gram = 1000 mg. Multiply grams by 1000 to get milligrams.
What is the grain symbol?
The symbol for grain is gr.
What is the gram symbol?
The symbol for gram is g.
Can I use this calculator for ammunition reloading?
Yes. This calculator is perfect for converting bullet weights and powder charges between grains and grams.
What is the difference between a grain and a gram?
A grain is an imperial unit of mass (≈ 0.0648 g), while a gram is a metric unit of mass. One gram is approximately 15.43 grains.
Is a grain the same as a gram?
No. A grain is much smaller than a gram. 1 gram ≈ 15.432 grains, so 1 grain ≈ 0.0648 grams.
What is the history of the grain unit?
The grain has been used as a unit of mass since antiquity, originally based on the weight of a single grain of barley or wheat. It was standardized in the 14th century and remains in use today.
How accurate is this calculator?
This calculator uses the exact conversion factor (0.06479891) and provides results with customizable decimal precision. It is accurate for all scientific and practical applications.