Convert Grains to Ounces
1 grain (gr) equals 0.002285714286 ounces (oz).
1 gr = 0.002285714286 oz
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk grain to ounce converter to paste a column from Excel.
How to Convert Grain to Ounce
- 1 gr = 0.002285714286 oz
- 1 oz = 437.5 gr
- Example: convert 15 gr to oz: 15 gr = 15 × 0.002285714286 oz = 0.03428571429 oz
Reference conditions. gr: Avoirdupois system: 1 lb = 16 oz = 7000 grains = 0.45359237 kg exactly (1959 agreement). oz: Avoirdupois system: 1 lb = 16 oz = 7000 grains = 0.45359237 kg exactly (1959 agreement).
Formula
oz = gr × 0.002285714285714
or oz = gr ÷ 437.5
Derivation from SI units:
- 1 gr = 1/7000 lb = 64.79891 mg (exact)
- 1 oz = 1/16 lb = 28.349523125 g (exact)
- 1 gr = 0.00006479891 kg ÷ 0.028349523125 kg per oz = 0.002285714285714 oz
Both units are defined exactly, so the factor is exact. Grain definition: grain; Ounce definition: ounce.
Worked examples
- A reading of 40 gr converts to 0.09142857143 oz.
40 gr × 0.002285714286 = 0.09142857143 oz - A value of 150 gr is 0.3428571429 oz.
150 gr × 0.002285714286 = 0.3428571429 oz
Grain to Ounce conversion table
| Grains (gr) | Ounces (oz) |
|---|---|
| 1 gr | 0.002285714286 oz |
| 5 gr | 0.01142857143 oz |
| 10 gr | 0.02285714286 oz |
| 15 gr | 0.03428571429 oz |
| 20 gr | 0.04571428571 oz |
| 40 gr | 0.09142857143 oz |
| 55 gr | 0.1257142857 oz |
| 100 gr | 0.2285714286 oz |
| 115 gr | 0.2628571429 oz |
| 124 gr | 0.2834285714 oz |
| 150 gr | 0.3428571429 oz |
| 180 gr | 0.4114285714 oz |
| 300 gr | 0.6857142857 oz |
| 1000 gr | 2.285714286 oz |
| 7000 gr | 16 oz |
Where it's used
Grains are used for bullet and powder weights, while ounces appear in food and parcel weights in the US. Both measure mass (commonly called weight), so the conversion is a fixed factor.
Grain to other weight and mass units
| Conversion | 1 gr equals |
|---|---|
| grain to kilogram | 0.00006479891 kg |
| grain to gram | 0.06479891 g |
| grain to milligram | 64.79891 mg |
| grain to microgram | 64798.91 µg |
| grain to metric ton | 6.479891 × 10⁻⁸ t |
| grain to pound | 0.0001428571429 lb |
| grain to ounce | 0.002285714286 oz |
| grain to stone | 0.00001020408163 st |
| grain to short ton | 7.142857143 × 10⁻⁸ ton (US) |
| grain to long ton | 6.37755102 × 10⁻⁸ ton (UK) |
| grain to troy ounce | 0.002083333333 oz t |
| grain to carat | 0.32399455 ct |
Frequently asked questions
How many ounces are in 1 grain?
1 gr = 0.002285714286 oz.
How do I convert grains to ounces?
Multiply the value in gr by 0.002285714286, or divide it by 437.5. For example, 15 gr × 0.002285714286 = 0.03428571429 oz.
Is the gr to oz conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "grain (gr)".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "ounce (avoirdupois) (oz)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Grains to Ounces. Retrieved October 17, 2026, from https://scientificconverters.com/mass/grains-to-ounces/
IEEE
Scientific Converters, "Convert Grains to Ounces," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/grains-to-ounces/