How many cups is one medium onion?

One medium onion is 0.66 cups. The conversion scales in a straight line, so 2 onions is 1.32 cups and 3 onions is 1.98 cups. Multiply or divide that figure to match whatever your recipe needs, or use the converter above for an exact reading at any amount.

How many grams is one medium onion?

One medium onion weighs about 110 grams. A small one is about 70 grams and a large one about 150 grams, so set the size selector to match what you actually have. The converter above and the chart below cover all sizes and units for any amount.

Convert Onion from Whole Onions

Onion converter

Use the tool below to convert onion from Whole Onions to the measurement that you need.

Onion size swings from a 70 g small to a 150 g large, more than double. Setting the size below means “1 cup chopped” comes out right whether your onions are small or jumbo.

How much is one medium onion?

One medium onion is 0.66 cups, about 110 grams. 2 onions is 1.32 cups and 3 onions is 1.98 cups. Use the converter below for any amount.

Out of onion? See onion substitutes →

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 our Garlic converter.

Enter an amount, pick your units, and set the size for counting whole onions.

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Onion sizeSize applies to whole onions (small / medium / large).

Result

0.66 cups

Common Onion conversions

Quick reference for onion at medium size. Switch the size in the converter above for small or large.

onions	Cups (chopped)
1 onion	0.66 cups
2 onions	1.32 cups
3 onions	1.98 cups
4 onions	2.63 cups
5 onions	3.29 cups
6 onions	3.95 cups

Onion conversion chart

The chart below shows how whole onions (medium size) convert to cups, grams and ounces.

onions	cups	cups (US)	g	oz	lb
1 onion	0.66 cups	0.69 cups (US)	110 g	3.88 oz	0.24 lb
2 onions	1.32 cups	1.38 cups (US)	220 g	7.76 oz	0.49 lb
3 onions	1.98 cups	2.06 cups (US)	330 g	11.64 oz	0.73 lb
4 onions	2.63 cups	2.75 cups (US)	440 g	15.52 oz	0.97 lb
5 onions	3.29 cups	3.44 cups (US)	550 g	19.4 oz	1.21 lb

Onion varieties and best uses

The conversions above are the same whatever variety you use; the difference is what each is good for. Here is how the common onion varieties compare.

Variety	Best for
Yellow / brown	All-purpose cooking, soups, caramelising: balanced and sweetens when cooked.
Red	Raw in salads and pickling: mild, colourful; also good roasted.
White	Mexican dishes and salsa: sharp and clean raw.
Sweet (Vidalia / Walla Walla)	Onion rings and raw slices: low pungency, high sugar.
Shallot	Dressings and pan sauces: delicate, subtle flavour.

Which should I pick?

For everyday cooking, soups, and caramelising, a yellow / brown onion is the default, with the most balanced flavour. For raw use in salads, salsa, or pickling, a red or sweet (Vidalia / Walla Walla) onion is milder. White onions suit Mexican dishes; shallots are the delicate choice for dressings and pan sauces.

Frequently Asked Questions

How much is one medium onion?: One medium onion is 0.66 cups, or 110 grams. The ratio is fixed, so 2 onions is 1.32 cups and 3 onions is 1.98 cups. Use the converter above for any amount, or the chart below for the most common quantities. Open the onion converter
How many cups is one medium onion?: One medium onion is 0.66 cups. The conversion scales in a straight line, so 2 onions is 1.32 cups and 3 onions is 1.98 cups. Multiply or divide that figure to match whatever your recipe needs, or use the converter above for an exact reading at any amount.
How many grams is one medium onion?: One medium onion weighs about 110 grams. A small one is about 70 grams and a large one about 150 grams, so set the size selector to match what you actually have. The converter above and the chart below cover all sizes and units for any amount.

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