Fruit & Vegetables
Convert ounces of chopped onion to cups
One ounce of chopped onion weighs about 0.177 cup, and half a ounce comes to roughly 0.089 cup. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 oz of chopped onion =
0.177 cup
About 1/8 cup in recipe notation
- ml
- 41.9
- tbsp
- 2.83
Chopped Onion: 160 g per US cup · USDA FoodData Central. One medium onion yields about 1 cup chopped. Finely minced onion packs denser.
Full chopped onion chart →Chopped Onion at a glance
Every number on this page comes from a single figure: 160 grams per US cup (USDA FoodData Central).
- 1 cup
- 160 g
- 1 tablespoon
- 10 g
- 1 teaspoon
- 3.33 g
- 1 cup in ounces
- 5.64 oz
- 100 g in cups
- 0.625 cups
- Density
- 0.68 g/ml
ounces to cups chart for chopped onion
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Ounces (weight) | Cups (US) | Tablespoons (US) | Millilitres |
|---|---|---|---|
| 0.5 oz | 0.089 cup | 1.42 tbsp | 21 ml |
| 1 oz | 0.177 cup | 2.83 tbsp | 41.9 ml |
| 2 oz | 0.354 cup | 5.67 tbsp | 83.8 ml |
| 3 oz | 0.532 cup | 8.5 tbsp | 126 ml |
| 4 oz | 0.709 cup | 11.3 tbsp | 168 ml |
| 5 oz | 0.886 cup | 14.2 tbsp | 210 ml |
| 6 oz | 1.06 cup | 17 tbsp | 252 ml |
| 8 oz | 1.42 cup | 22.7 tbsp | 335 ml |
| 12 oz | 2.13 cup | 34 tbsp | 503 ml |
| 16 oz | 2.83 cup | 45.4 tbsp | 671 ml |
How this conversion is calculated
Volume-to-weight conversions are only as good as the density behind them. We treat chopped onion as 160 g per US customary cup, which works out to 0.676 g/ml. From there:
- Your ounces figure is converted into millilitres or grams using standard unit sizes (oz = 28.3 g).
- The density above bridges volume and weight in whichever direction you need.
- The result is rounded the way a cook would round it — to the nearest gram, or to a usable fraction such as 5/8 cups.
Measuring chopped onion accurately
One medium onion yields about 1 cup chopped. Finely minced onion packs denser.
If a recipe matters to you — bread, macarons, anything with a tight hydration or ratio — weigh it. A £10 digital scale removes the single largest source of variation in home baking, and it is faster than washing three measuring cups.
When cups are fine
- Liquids measured in a proper jug, where volume is the honest unit anyway.
- Forgiving savoury cooking: soups, stews, stir-fries, marinades.
- Small amounts of leaveners and spices, as long as you use level spoons.
Frequently asked questions
How many cups are in 1 ounce of chopped onion?
1 ounce of chopped onion is 0.177 cup. This is based on a density of 160 g per US cup.
How many cups are in 2 ounces of chopped onion?
2 ounces of chopped onion is 0.354 cup, and 0.089 cup for half a ounce.
How much is 100 g of chopped onion in cups?
100 g of chopped onion is about 5/8 cups. Weight is always the more reliable measurement, so use a scale when the recipe gives grams.
Why do other sites give a different number for chopped onion?
One medium onion yields about 1 cup chopped. Finely minced onion packs denser.
Do UK and Australian cups give the same result?
No. A US customary cup is 236.6 ml, a metric cup used in Australia and New Zealand is 250 ml, and an old UK imperial cup is 284 ml. Our default is the US cup, but you can pick metric cups in the converter.