The avoirdupois ounce (US customary) and the gram (metric) both have exact definitions, making this a precise weight conversion.
How it works
Multiplying ounces by 28.349523125 gives grams; dividing grams by that same constant gives ounces back. Type into either field and the other updates instantly.
What this does not include
This does not include the troy ounce, a heavier unit used for precious metals like gold and silver — this calculator uses the standard avoirdupois ounce for everyday weight.
How to use this calculator
- Enter a value in either ounces or grams — the other field fills in automatically.
Frequently asked questions
Is this the same conversion as the site’s g-to-oz calculator?
Yes, functionally identical — this version leads with ounces first, for anyone specifically searching “oz to grams” rather than “grams to oz.”
Why is 16 ounces exactly 453.59237 grams?
Because 16 ounces equals exactly 1 avoirdupois pound, and the international pound was fixed in 1959 at exactly 453.59237 grams.
Where is this conversion most commonly needed?
Cooking (comparing US-ounce and metric-gram recipes), postal weight, and nutrition labeling comparisons between countries.
