Ounces to Grams Converter
1 avoirdupois ounce = 28.349523125 grams.
Conversion result
Grams = avoirdupois ounces × 28.349523125; ounces = grams ÷ 28.349523125.
Primary source: NIST SP 811, Appendix B.8 conversion factors. Published SI table values may be rounded; this converter uses the exact underlying definitions. NIST Handbook 44, Appendix C supplies the underlying inch, pound and US liquid measure definitions. NIST SP 1038, footnote 19 defines the US cup, tablespoon and teaspoon in fluid ounces.
Worked example: 2 mass ounces × 28.349523125 = 56.69904625 grams.
Common conversion values
The table follows the selected direction. Results display up to 12 significant digits; exact definitions are used before display rounding.
| avoirdupois ounces (mass) | grams |
|---|---|
| 0.5 | 14.1747615625 |
| 1 | 28.349523125 |
| 2 | 56.699046250 |
| 4 | 113.398092500 |
| 8 | 226.796185000 |
The international avoirdupois pound is exactly 453.59237 grams and contains 16 ounces, so one ounce is 453.59237 ÷ 16 grams. This is mass; fluid ounces measure volume and troy ounces use a different mass.
These are mass conversions using the international avoirdupois system. Fluid ounces describe volume and require a different conversion. Troy weight is outside this page’s accepted units.
How to use this tool
Enter a quantity in avoirdupois ounces (mass), choose the forward or reverse direction, and select Convert. Decimals, fractions such as 1/2, and mixed fractions such as 1 1/2 are supported.
Frequently asked questions
Are these fluid or troy ounces?
Neither. These are avoirdupois ounces of mass. Fluid ounces need a volume conversion; troy ounces use a different factor.
Can I reverse the conversion or enter a fraction?
Yes. Choose the reverse direction on this same page. Enter a nonnegative decimal, fraction such as 3/4, or mixed fraction such as 1 1/2. Zero is accepted; the quantity and fraction components are limited to 10¹², and a denominator must be positive.
Is this converter free and private?
Yes. Conversions run on your device without uploading your entries or saving them to browser storage. There is no sign-up.