Ounce to Grain Converter
Weight · unit-converter
Convert Ounce to Grain with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations use gram-based factors (international avoirdupois pound and metric definitions). The full Weight Converter also includes carat, grain, and US/UK hundredweight.
Calculator
From: Ounce (oz)
To: Grain (gr)
About Ounce
The avoirdupois ounce is 1/16 of an avoirdupois pound (about 28.35 g). Cooking and postal weights often use ounces.
About Grain
The grain is 1/7000 of a pound (exactly 64.79891 mg). It is used in ballistics, pharmacy, and precious-metal contexts.
How to convert ounces to grains
1 ounce is equal to 437.5 grain:
1 oz = (28.349523125 g ÷ 0.06479891 g) gr = 437.5 gr
Each ounce is defined as 28.349523125 g and each grain as 0.06479891 g, so one oz equals 28.349523125 ÷ 0.06479891 gr = 437.5 gr.
Let w(oz) be the numeric value of the same mass measured in Ounce (oz), and w(gr) the value in Grain (gr). Then:
w(gr) = w(oz) × (28.349523125 / 0.06479891)
Equivalently, divide by how many oz fit into one gr (grams per gr divided by grams per oz):
w(gr) = w(oz) ÷ 0.00228571428571
Or: grain = ounce ÷ 0.00228571428571
Examples
Example #1: Convert 20 oz to grain
20 oz = 20 oz × (28.349523125/0.06479891) gr = 8750 gr
20 oz = 20 oz ÷ 0.00228571428571 = 8750 gr
Example #2: Convert 50 oz to grain
50 oz = 50 oz × (28.349523125/0.06479891) gr = 21875 gr
50 oz = 50 oz ÷ 0.00228571428571 = 21875 gr
Summary
To convert Ounce to Grain, multiply the value in oz by the ratio of grams per oz divided by grams per gr. Equivalently: value_gr = value_oz × (28.349523125 / 0.06479891). Numerically, 1 oz equals 437.5 gr.
Relationship context
Both units belong to imperial / UK (stone, long ton, pound, ounce). Relationships such as 16 oz per lb and 14 lb per stone are exact in the avoirdupois system; tons use fixed pound counts. This tool uses international definitions tied to the kilogram.
Conversion tables
| Ounce (oz) | Grain (gr) |
|---|---|
| 0.1 | 43.75 |
| 1 | 437.5 |
| 2 | 875 |
| 3 | 1,312.5 |
| 4 | 1,750 |
| 5 | 2,187.5 |
| 6 | 2,625 |
| 7 | 3,062.5 |
| 8 | 3,500 |
| 9 | 3,937.5 |
| Ounce (oz) | Grain (gr) |
|---|---|
| 10 | 4,375 |
| 20 | 8,750 |
| 30 | 13,125 |
| 40 | 17,500 |
| 50 | 21,875 |
| 60 | 26,250 |
| 70 | 30,625 |
| 80 | 35,000 |
| 90 | 39,375 |
| 100 | 43,750 |