Free Online Ounces to Grams

1. Type a value into either the Ounces or Grams field.
2. The other field updates instantly using the avoirdupois factor.
3. For fluid ounces (volume), use the cups-to-ml or volume converter instead.

There are several different ounces still in active use, and using the wrong one is the single most common conversion mistake. This tool uses the avoirdupois ounce — the everyday weight ounce found on food labels, postage scales and chocolate bars. It's defined as exactly 28.349523125 g via the international pound.

The troy ounce (31.1035 g) is the one used for gold, silver and other precious metals; the fluid ounce (29.5735 ml in the US, 28.4131 ml in the UK) is a volume, not a weight. If you're pricing precious metals or measuring liquids, use the matching dedicated tool.

This page targets cooking and postage. A 4 oz chocolate bar is 113.4 g; a 16 oz (1 lb) box of pasta is 453.6 g; a 1 oz US shot of spirit is 29.6 ml of volume, not mass — note the unit.