The exact equivalent
An ounce is 28.3495 grams, so a gram is 0.0352740 ounces. The ounce here is the avoirdupois ounce, the one used for everything except precious metals.
1 g = 0.03527396 oz
1 oz = 28.34952313 g
How to convert it by hand
Just multiply by the conversion factor. To go from grams to ounces, multiply by 0.035274; to come back, divide by that same number or multiply by 28.349523.
For example: 25 g × 0.035274 = 0.8818 oz.
A tip that saves mistakes: check the result goes the way you expect. If ounces are a smaller unit than grams, the number has to come out bigger. If it comes out smaller, you divided when you should have multiplied.
Conversion table
| g | oz |
|---|---|
| 1 | 0.0353 |
| 2 | 0.0705 |
| 5 | 0.1764 |
| 10 | 0.3527 |
| 20 | 0.7055 |
| 50 | 1.7637 |
| 100 | 3.5274 |
Reference points to picture it
| Reference | Equals |
|---|---|
| A slice of bread | 30 g = 1.06 oz |
| A standard chocolate bar | 100 g = 3.53 oz |
| A tin of beans | 400 g = 14.1 oz |
| A bag of flour | 1,000 g = 35.3 oz |
The trick for doing it in your head
Divide by 28 and add about 1%. For 100 g: 100 ÷ 28 = 3.57, so roughly 3.5 ounces against a true 3.53.
It is fine for getting by without a phone, but not for anything that depends on precision: in a recipe, on a building site or in a dose, use the exact conversion.