Recipes often call for one small, medium, or large onion without any indication of the amount in cups of chopped onions these sizes should yield. For example, if all you have is small onions, how many do you need to equal one large onion? The following table gives the general size, weight and the amount in cups of each size onion.

This information should correspond to the common varieties of onions such as yellow, white, red, or sweet.
When buying onions, keep in mind that there is no advantage to buying the largest onions you can find. Smaller onions are easier to chop, and you will be more likely to use the entire onion in a dish so that you won’t have to store unused portions of onion.
More Onion and Yields Reading
- Should I Use White or Yellow Onions?
- What’s the Difference Between Scallions and Green Onions?
- How Many Carrots are in a Pound?
- How Many Slices of Bacon for Crumbled Cups?