Convert Onion from Ounces to US cups (chopped)
Use the tool below to convert onion from Ounces to US cups (chopped).
How many US cups is an ounce of onions?
An ounce of onions is about 0.18 US cups. Half that is about 0.09 US cups and double about 0.35 US cups, so the ratio scales in a straight line. Use the converter above for any amount, or the chart below for the most common quantities.
Related Onion Ingredients
Already chopping? The chopped onion converter moves straight between cups, grams, and spoons of prepped onion. See our Chopped Onion converter.
Need a milder, more delicate allium? Shallots (20–60 g) suit dressings and pan sauces. See our Shallot converter.
Spring onions (10–25 g) are tender and herbaceous, great raw or as a garnish. See our Spring Onion converter.
Mincing garlic for the same dish? Garlic cloves (2–7 g) bring pungent bite where onion brings sweet body. See what an ounce of cloves is in US cups.
Want a crisp, peppery bite? Radishes (8–25 g) are sharp and crunchy, good raw in slaws or quick pickles. See our Radish converter.
Out of onion? See onion substitutes →
No scale? The tool below gives a good estimate, but for exact bakes a digital kitchen scale removes the guesswork.
Weigh it exact, get a scaleOnion converter tool
Enter an amount, pick your units, and set the size for counting whole onions.
Result
0.18 cups (US)Onion Calculators & Kitchen Tools
Working with onion? These tools handle the jobs a converter cannot.
- Oven to Air Fryer Converter Match the temperature and time when you swap the oven for an air fryer, fan oven, or slow cooker.
- Recipe Scaler Scale any recipe up or down and keep every ingredient in ratio.
Common Onion conversions
Quick reference for onion at medium size. Switch the size in the converter above for small or large.
| Ounces | US cups (chopped) |
|---|---|
| 1 oz | 0.18 cups (US) |
| 2 oz | 0.35 cups (US) |
| 4 oz | 0.71 cups (US) |
| 8 oz | 1.42 cups (US) |
| 16 oz | 2.83 cups (US) |
| 32 oz | 5.67 cups (US) |
Frequently Asked Questions
- How many US cups is an ounce of onions?
- An ounce of onions is about 0.18 US cups of onion. The density of chopped onion is fixed, so the ratio holds at any amount: double the ounces and you double the US cups. Use the converter above for any quantity, or the chart above for the most common amounts. Open the onion converter
- How many US cups is 2 ounces of onions?
- 2 ounces of onions is about 0.35 US cups. The ratio is fixed, so an ounce of onions is 0.18 US cups and the figure scales in a straight line as you multiply or divide. Scaling a recipe up or down keeps the same proportion, so work from whichever amount your recipe lists. Use the converter above for any other quantity of onion.
- How many ounces of onions is 0.18 US cups?
- 0.18 US cups of onions is about 1.02 ounces. The conversion works the same in reverse, so you can switch between ounces and US cups without changing the result. This helps when a recipe lists one unit but you would rather measure the other. Use the converter above for any amount.
- What is the difference between a metric and US cup?
- A metric cup holds 250 ml while a US cup holds 240 ml, so a US cup is 4% smaller. For chopped onion that gap is small but real, and it adds up across several cups. The guide linked below explains when the difference matters and how to switch between the two so a recipe lands right whichever cup you own. metric v US cup