How many grams in a cup of water?

1 cup of water weighs about 237 g, because a US cup holds 236.6 mL and 1 mL of water weighs about 1 g. King Arthur Baking lists 227 g.

Sources: US cup volume (NIST), King Arthur Baking ingredient weight chart · Checked October 10, 2026

Amount

Unit

237 g 8.3 oz

Sources range from 227 g to 237 g for 1 cup.

Converting a whole recipe?

Sous Chef converts every ingredient in a recipe to grams and millilitres in one tap, rounded to amounts you would actually weigh.

Water cups to grams table

Using 237 g per US cup. A US cup is 236.6 mL; 1 cup is 16 tablespoons.

Water cups to grams
US cups	Grams	Ounces	Tablespoons
⅛ cup	30 g	1 oz	2
¼ cup	59 g	2.1 oz	4
⅓ cup	79 g	2.8 oz	5.3
½ cup	118 g	4.2 oz	8
⅔ cup	158 g	5.6 oz	10.7
¾ cup	177 g	6.3 oz	12
1 cup	237 g	8.3 oz	16
1½ cups	355 g	12.5 oz	24
2 cups	473 g	16.7 oz	32
3 cups	710 g	25 oz	48
4 cups	946 g	33.4 oz	64

Why sources disagree

King Arthur rounds a cup of water to 8 ounces by weight, which is 227 g. Measured by volume, a US cup is 236.6 mL, so a full cup of water weighs about 237 g. A metric cup used in the UK, Australia and Canada is 250 mL, which is 250 g of water.

Source	Listed as	Grams per cup
US cup volume (NIST) 1 US fluid ounce = 29.57 mL; 1 cup = 8 fl oz	1 cup = 236.6 mL, about 237 g of water	237 g
King Arthur Baking ingredient weight chart Water	1 cup = 227 g	227 g

Bold row is the figure the calculator uses. Figures listed for a smaller measure are multiplied up to one cup.

How to measure water accurately

Weighing water is quick, but a clear measuring cup is accurate enough for most cooking.
Weigh on a digital scale when you can, since it skips the mess of measuring cups.
Use a clear liquid measuring cup on a flat counter and read it at eye level.

Convert the whole recipe, not one line

Converting a recipe one ingredient at a time is where mistakes slip in. Sous Chef imports a recipe from a link or pasted text, then converts every ingredient at once: dry ingredients and butter to grams, liquids to millilitres. Tap again to go back to cups.

US recipe

2¼ cups all-purpose flour
1 cup butter, softened
¾ cup brown sugar, packed
1½ cups milk

In Sous Chef, after "Convert to metric"

275 g all-purpose flour
225 g butter, softened
170 g brown sugar, packed
350 ml milk

Example output. Sous Chef rounds to amounts you would actually weigh, so its numbers can differ by a few grams from the table above.

Common questions

How many grams is half a cup of water?

Half a cup of water is about 118 g, using 237 g per cup.

How many grams is 1 tablespoon of water?

1 tablespoon of water is about 15 g, since 1 cup is 16 tablespoons and 237 g per cup divided by 16 is 15 g.

More conversions

Cook in grams without doing the math.

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