How many grams in a cup of peanut butter?

1 cup of peanut butter weighs 258 g by USDA's figure for smooth peanut butter. King Arthur Baking lists 135 g per half cup, which is 270 g per cup.

Sources: USDA FoodData Central, King Arthur Baking ingredient weight chart · Checked October 10, 2026

Amount

Unit

258 g 9.1 oz

Sources range from 258 g to 270 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.

Peanut butter cups to grams table

Using 258 g per US cup. A US cup is 236.6 mL; 1 cup is 16 tablespoons.

Peanut butter cups to grams
US cups	Grams	Ounces	Tablespoons
⅛ cup	32 g	1.1 oz	2
¼ cup	65 g	2.3 oz	4
⅓ cup	86 g	3 oz	5.3
½ cup	129 g	4.6 oz	8
⅔ cup	172 g	6.1 oz	10.7
¾ cup	194 g	6.8 oz	12
1 cup	258 g	9.1 oz	16
1½ cups	387 g	13.7 oz	24
2 cups	516 g	18.2 oz	32
3 cups	774 g	27.3 oz	48
4 cups	1,032 g	36.4 oz	64

Why sources disagree

Peanut butter is thick and traps air pockets when you spoon it into a cup, so cup measurements vary. The sources are 12 g apart. Weighing it straight into the bowl is easier and cleaner than scraping a measuring cup.

Source	Listed as	Grams per cup
USDA FoodData Central Peanut butter, smooth style, without salt	1 cup = 258 g	258 g
King Arthur Baking ingredient weight chart Peanut butter	½ cup = 135 g	270 g

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

How to measure peanut butter accurately

Stir natural peanut butter well first, because the oil settles on top.
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 peanut butter?

Half a cup of peanut butter is about 129 g, using 258 g per cup.

How many grams is 1 tablespoon of peanut butter?

1 tablespoon of peanut butter is about 16 g, since 1 cup is 16 tablespoons and 258 g per cup divided by 16 is 16 g.

More conversions

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