This converter turns grains into ounces instantly, using the exact factor 1 grain = 0.002285714286 ounces. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
The oldest English mass unit, now used for bullets, arrows and propellant charges. The avoirdupois ounce, exactly 28.349523125 grams — standard in US recipes.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
grains- The amount you are converting, measured in grains
0.002285714286- The exact number of ounces in one grain
ounces- The converted result
How it works, step by step
- Enter the number of grains you want to convert.
- The value is multiplied by 0.002285714286, the exact conversion factor.
- The result is displayed in ounces, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 grains
Multiply 5 by 0.0022857143. That gives 0.011429 ounces. A quick sanity check: one grain is smaller than one ounce, so the number should get smaller — and it does.
Converting 72 grains
72 × 0.0022857143 = 0.164571 ounces. Working backwards, 0.164571 ÷ 0.0022857143 returns 72 grains, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many ounces are in one grain?
Exactly 0.002285714286. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert grains to ounces?
Ounces = grains × 0.002285714286. To reverse it, divide instead: grains = ounces ÷ 0.002285714286, which is the same as multiplying by 437.5.
Is the grain bigger than the ounce?
No. One grain is only 0.00228571 of a ounce, so the ounce is the larger unit.
Why does my answer differ slightly from other grains to ounces converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a grain?
The oldest English mass unit, now used for bullets, arrows and propellant charges.
What is a ounce?
The avoirdupois ounce, exactly 28.349523125 grams — standard in US recipes.
Grains to ounces reference table
| Grains | Ounces |
|---|---|
| 0.5 gr | 0.001143 oz |
| 1 gr | 0.002286 oz |
| 2 gr | 0.004571 oz |
| 3 gr | 0.006857 oz |
| 5 gr | 0.011429 oz |
| 10 gr | 0.022857 oz |
| 15 gr | 0.034286 oz |
| 20 gr | 0.045714 oz |
| 25 gr | 0.057143 oz |
| 50 gr | 0.114286 oz |
| 75 gr | 0.171429 oz |
| 100 gr | 0.228571 oz |
| 250 gr | 0.571429 oz |
| 500 gr | 1.1429 oz |
| 1000 gr | 2.2857 oz |
Exact factor: 1 grain = 0.002285714286 ounces. Values rounded for display.