How Many Grams in an Ounce?
There are 28.349523125 grams in one ounce, usually rounded to 28.35 grams.
How to Convert Ounces to Grams
To convert ounces to grams, multiply by 28.3495.
For example: 5 ounces × 28.3495 = 141.748 grams.
Why This Number Matters
Nutrition labels, coffee doses, baking recipes and postal weights all need this number. It is the bridge between American recipe quantities and any kitchen scale set to metric.
A 1-ounce serving of cheese is 28.3495 grams, which is why labels list it as 28 g.
What People Get Wrong
A troy ounce is 31.1034768 grams, about 10 percent heavier. Gold and silver prices quoted per ounce always mean troy ounces.
Ounces to Grams Conversion Table
| Ounces (oz) | Grams (g) |
|---|---|
| 1 | 28.3495 |
| 2 | 56.699 |
| 3 | 85.0486 |
| 4 | 113.398 |
| 5 | 141.748 |
| 6 | 170.097 |
| 7 | 198.447 |
| 8 | 226.796185 |
| 9 | 255.146 |
| 10 | 283.495 |
| 11 | 311.845 |
| 12 | 340.194 |
| 13 | 368.544 |
| 14 | 396.893 |
| 15 | 425.243 |
| 16 | 453.59237 |
| 17 | 481.942 |
| 18 | 510.291 |
| 19 | 538.641 |
| 20 | 566.99 |
| 25 | 708.738 |
| 30 | 850.486 |
| 40 | 1,133.98 |
| 50 | 1,417.48 |
| 75 | 2,126.21 |
| 100 | 2,834.95 |
| 250 | 7,087.38 |
| 500 | 14,174.8 |
| 1,000 | 28,349.5 |
About These Units
The ounce
An avoirdupois ounce is one sixteenth of a pound, or exactly 28.349523125 grams. Do not confuse it with the fluid ounce, which measures volume, not weight.
The gram
A gram is one thousandth of a kilogram, roughly the weight of a paperclip. Nutrition labels worldwide, and increasingly American baking recipes, are written in grams.
Definitions follow NIST Special Publication 811, Appendix B. See how we calculate for the exact values and rounding rules.
Frequently Asked Questions
Is an ounce exactly 28.35 grams?
Not quite. It is exactly 28.349523125 grams; 28.35 is the usual rounding and is accurate to better than two parts in a million.
How many grams in 8 ounces?
8 ounces is 226.796 grams, which packaging normally rounds to 225 g or 227 g.
How many grams in a pound?
A pound is 453.59237 grams.
How many ounces in 100 grams?
100 grams is 3.5274 ounces.