What Size are Small, Medium and Large Onions and How Much Does Each Yield Chopped?

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.

Onion Size Approx. Size Weight Amount Chopped
Small Lemon 4 oz (0.25lbs) 1/2 cup
Medium Navel Orange 8 oz (0.5lbs) 1 cup
Large Small Grapefruit 16 oz (1lbs) 2 cups

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.

Yellow Spanish onions, small size
Yellow “Spanish” Onions, Small Size