Diced Onion
One US cup of diced onion weighs between 113 and 172 grams (4 to 6.1 ounces), depending on how the cup is filled and which source measured it. Use 150 grams (5.3 ounces) for a 1/4-inch dice spooned into the cup and leveled. Every figure behind it is below, with the method each source used.
Also called chopped onion, chopped onions, diced onions, diced yellow onion, onion diced.
Most sites print one number for a cup of diced onion. This page prints 113 to 172 grams, because that is what USDA SR Legacy "Onions, raw" (FDC 170000), Health Canada, Nutrient Value of Some Common Foods (2008), USDA Food Buying Guide for Child Nutrition Programs, onions, fresh, diced 1/4-inch, prepackaged, USDA Food Buying Guide for Child Nutrition Programs, onions, fresh whole, chopped, The Culinary Institute of America, Conversions chart and King Arthur Baking Ingredient Weight Chart actually measured, and it names the method behind every figure rather than picking a favourite.
Two or more sources describe the same way of filling the cup and still disagree, by 52.2%. That is more than this site will average over, so all the figures stand and none is chosen. Sources span 113-172 g per cup, a 52% gap, over the 10% tolerance. USDA's chopped onion is 160 g and Health Canada's 162 g; USDA's school Food Buying Guide gives 145-172 g for diced and chopped onion; King Arthur gives 142 g; the Culinary Institute of America gives 113 g for diced. The size of the dice and how hard the cup is filled decide it. No single figure is published.
| Volume | Grams | Ounces |
|---|---|---|
| 1 cup | 113–172 g | 4–6.1 oz |
| 3/4 cup | 84.7–129 g | 3–4.6 oz |
| 2/3 cup | 75.3–114.7 g | 2.7–4 oz |
| 1/2 cup | 56.5–86 g | 2–3 oz |
| 1/3 cup | 37.7–57.3 g | 1.3–2 oz |
| 1/4 cup | 28.2–43 g | 1.00–1.5 oz |
| 1 tablespoon | 7.1–10.7 g | 0.25–0.38 oz |
| 1 teaspoon | 2.4–3.6 g | 0.08–0.13 oz |
| Filling the cup | 1 cup | Source |
|---|---|---|
| Standard, raw, diced or chopped, spooned and leveled | 160 g5.6 oz | USDA SR Legacy "Onions, raw" (FDC 170000) |
| Standard, raw, diced or chopped, spooned and leveled | 161.7 g5.7 oz | Health Canada, Nutrient Value of Some Common Foods (2008) |
| Standard, raw, diced or chopped, spooned and leveled | 151 g5.3 oz | USDA Food Buying Guide for Child Nutrition Programs, onions, fresh, diced 1/4-inch, prepackaged |
| Standard, raw, diced or chopped, spooned and leveled | 172 g6.1 oz | USDA Food Buying Guide for Child Nutrition Programs, onions, fresh whole, chopped |
| Standard, raw, diced or chopped, spooned and leveled | 113 g4 oz | The Culinary Institute of America, Conversions chart |
| Standard, raw, diced or chopped, spooned and leveled | 142 g5 oz | King Arthur Baking Ingredient Weight Chart |
Diced Onion ounces to grams and cups
| Weight | Grams | US cups |
|---|---|---|
| 1 oz | 28.3 g | 0.16–0.25 |
| 4 oz | 113.4 g | 0.66–1.00 |
| 8 oz | 226.8 g | 1.32–2.01 |
| 16 oz (1 lb) | 453.6 g | 2.64–4.01 |
Compared side by side
Chopped vegetables compared: cup weights side by side, the source behind each, and why they differ.
Why this page publishes a range
A cup of diced onion weighs 113 to 172 g (4 to 6.1 oz), depending on how fine the dice is and how hard the cup is filled. USDA's chopped onion is 160 g, the USDA school Food Buying Guide's 1/4-inch dice is 151 g, King Arthur says 142 g and the Culinary Institute of America 113 g. The sources disagree by far more than the 10% tolerance, so this entry publishes the range.
Onion is about 89% water by USDA's figures, and its flesh is nearly as dense as water. So the onion itself is not what varies; the air between the pieces is. Small pieces from a fine chop nest into each other and leave little air, while a coarse half-inch dice stacks like building blocks with gaps at every corner. Moisture matters too: chopped onion gives up juice and slumps, so a cup filled with freshly chopped onion and pressed down weighs more than one spooned in loosely.
USDA SR Legacy "Onions, raw" (FDC 170000) lists 1 cup chopped at 160 g and 1 tablespoon chopped at 10 g, which agree, and 1 cup sliced at 115 g. Health Canada's table gives chopped yellow onion at 41 g per 60 mL, 162 g per US cup. USDA's Food Buying Guide, the yield tables used in US school kitchens, gives about 3 cups per pound for prepackaged 1/4-inch diced onion, 151 g per cup, and works out to 172 g per cup for whole onions chopped by hand. The Culinary Institute of America's conversion chart gives 1 cup diced at 4 oz, 113 g, and a medium onion at about 1 3/4 cups diced.
King Arthur lists diced onion at 1 cup = 5 oz = 142 g, inside the range. The same 5 oz appears in King Arthur's chart for diced carrots, celery and bell peppers and for sliced olives, which have very different shapes and water contents, so it reads as a round working figure rather than a measurement of each vegetable; for onion it happens to fall in the middle.
Frozen chopped onion bags are no help: they print 85 g, the reference serving for vegetables, beside either 2/3 or 3/4 cup.
Practical guidance: for a typical 1/4-inch dice spooned into the cup and leveled, use 150 g; for a fine chop pressed down, 160 g; for a coarse half-inch dice, about 115-120 g. A medium onion, about 110 g trimmed by USDA's portion, gives roughly 3/4 cup chopped; a large one, 150 g, about 1 cup. When a recipe's flavour depends on the onion, as in a soffritto, French onion soup or a curry base, weigh it: the difference between a coarse and a fine cup is a third more onion.
Sources
Standard, raw, diced or chopped, spooned and leveled — no single figure published
Sources span 113-172 g per cup, a 52% gap, over the 10% tolerance. USDA's chopped onion is 160 g and Health Canada's 162 g; USDA's school Food Buying Guide gives 145-172 g for diced and chopped onion; King Arthur gives 142 g; the Culinary Institute of America gives 113 g for diced. The size of the dice and how hard the cup is filled decide it. No single figure is published.
- USDA SR Legacy "Onions, raw" (FDC 170000)160 g per cup5.6 ozUSDA Standard Release publishes 1 cup chopped = 160 g (density 0.676 g/mL), 1 tbsp chopped = 10 g and 1 cup sliced = 115 g. Water 89.1 g per 100 g.
- Health Canada, Nutrient Value of Some Common Foods (2008)161.7 g per cup5.7 ozOnions, yellow, chopped, raw: 60 mL = 41 g, which is 161.7 g per US cup (density 0.683 g/mL).
- USDA Food Buying Guide for Child Nutrition Programs, onions, fresh, diced 1/4-inch, prepackaged151 g per cup5.3 ozYield table: 1 lb as purchased = 1 lb (about 3 cups) ready to cook, 12.00 quarter-cup servings, which is 151 g per cup (density 0.639 g/mL).
- USDA Food Buying Guide for Child Nutrition Programs, onions, fresh whole, chopped172 g per cup6.1 ozYield table: 1 lb as purchased = 0.88 lb ready to cook, 9.30 quarter-cup servings per pound as purchased, which is 172 g per cup (density 0.726 g/mL).
- The Culinary Institute of America, Conversions chart113 g per cup4 ozOnion, 1 cup diced = 4 oz = 113 g (density 0.478 g/mL); 1 medium onion = about 1 3/4 cups diced = 7 oz = 198 g.
- King Arthur Baking Ingredient Weight Chart142 g per cup5 ozKA lists "Onions (fresh, diced)" at 1 cup = 5 oz = 142 g, density 0.600 g/mL; the same 5 oz as KA gives for diced carrots, celery, bell peppers and sliced olives.
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