1 ounce = 28.35 grams
Convert ounces to grams with an exact, internationally defined factor — 1 oz = 28.349523125 g (exact).
ounces to grams
Computed with the exact factor · NIST SP 811
| Ounce | Gram |
|---|---|
| 0.5 oz | 14.17 g |
| 1 oz | 28.35 g |
| 2 oz | 56.7 g |
| 3 oz | 85.05 g |
| 5 oz | 141.75 g |
| 10 oz | 283.5 g |
| 25 oz | 708.74 g |
| 50 oz | 1,417.48 g |
| 100 oz | 2,834.95 g |
Exact factor details
- Exact factor
- 1 oz = 28.35 g (exact definition)
- Significant digits
- up to 4 significant digits shown
- Data source
- NIST SP 811 — verified against official tables
Why oz to g trips people up
Weight and mass conversions between kilograms, pounds, and ounces. The avoirdupois pound has been defined as exactly 0.45359237 kilograms since 1959, so these conversions are exact by international agreement. One ounce is exactly 28.349523125 grams. A gram is one-thousandth of a kilogram — the standard unit in recipes worldwide.
In everyday use, pound and kilogram are compared directly, though the pound is technically a unit of mass in the avoirdupois system. For cooking, gym training, and shipping the distinction does not matter — the exact definition keeps every conversion consistent. Ounces and grams are linked through the same definition: one ounce is exactly 28.349523125 grams.
Use the quick-reference table for the amounts people actually look up, and the converter above for everything in between. Both are computed from the same factor at full precision, so the table and the converter can never disagree — there is no second, rounded copy of the data anywhere on this page.
Frequently asked questions
Is the oz to g conversion exact?
Yes. 1 oz = 28.349523125 g (exact) and 1 g = 0.001 kg (exact) are exact definitions, so the conversion is exact — results are rounded only for readability.
How do I convert oz to g in my head?
Multiply ounces by 28 — 4 oz is about 113 g.
Why do other sites show slightly different oz to g results?
They round at different steps. This page computes with the full-precision factor and rounds only the final displayed number, so small trailing digits can differ from sites that round earlier.