An approximate guide to how much chopped onion (in US cups) you can expect from different sizes of whole onions (e.g., yellow, white, or red onions).
Whole Onion Size
Typical Weight (approx.)
Chopped Yield (US Cups) (approx.)
Small Onion
3-4 oz / 85-115 g
1/2 cup
Medium Onion
5-6 oz / 140-170 g
1 cup
Large Onion
8-10 oz / 225-285 g
1 1/2 - 2 cups
Extra-Large / Jumbo Onion
12 oz+ / 340 g+
2 - 2 1/2 cups or more
Important Considerations for Onion Yield:
These are general estimates. The actual yield of chopped onion can vary based on:
The specific variety of onion.
The size and uniformity of the chop (fine dice vs. rough chop).
How much of the root and top ends are trimmed.
"Medium" is the most common size called for in recipes. If a recipe just says "1 onion," it usually implies a medium one.
This chart assumes a standard dice or chop. If slicing, the volume might appear different.
For precise amounts, especially for recipes where onion is a primary flavor component or for large batch cooking, measuring the chopped onion by volume or weight after chopping is recommended. (1 cup chopped onion ≈ 150-160g).