How many grams in a cup of baking soda?

1 teaspoon of baking soda weighs 4.6 g by USDA, which works out to about 221 g per cup. King Arthur Baking lists 3 g per half teaspoon.

Sources: USDA FoodData Central, King Arthur Baking ingredient weight chart · Checked October 22, 2026

Amount

Unit

221 g 7.8 oz

Sources range from 221 g to 288 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.

Baking soda cups to grams table

Using 221 g per US cup. A US cup is 236.6 mL; 1 cup is 16 tablespoons.

Baking soda cups to grams
US cups	Grams	Ounces	Tablespoons
⅛ cup	28 g	1 oz	2
¼ cup	55 g	1.9 oz	4
⅓ cup	74 g	2.6 oz	5.3
½ cup	111 g	3.9 oz	8
⅔ cup	147 g	5.2 oz	10.7
¾ cup	166 g	5.8 oz	12
1 cup	221 g	7.8 oz	16
1½ cups	332 g	11.7 oz	24
2 cups	442 g	15.6 oz	32
3 cups	663 g	23.4 oz	48
4 cups	884 g	31.2 oz	64

Why sources disagree

Recipes use baking soda by the teaspoon, so the gap that matters is small: 4.6 g per teaspoon by USDA against 6 g by King Arthur, whose chart rounds to whole grams on a half-teaspoon measure. Multiplied up to a cup, that rounding becomes a 67 g difference. Baking soda is strong, and too much leaves a soapy, metallic taste, so measure level spoons or weigh small amounts on a scale that reads to 0.1 g.

Source	Listed as	Grams per cup
USDA FoodData Central Leavening agents, baking soda	1 teaspoon = 4.6 g	221 g
King Arthur Baking ingredient weight chart Baking soda	½ teaspoon = 3 g	288 g

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

How to measure baking soda accurately

Level each spoon with a knife: a heaped teaspoon can hold far more than the recipe intends.
Do not add extra baking soda for more rise, since too much tastes soapy and can make baked goods collapse.
Use a scale that reads to 0.1 g for small amounts of leavening.

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 1 teaspoon of baking soda?

1 teaspoon of baking soda is 4.6 g by USDA. King Arthur Baking's 3 g per half teaspoon works out to 6 g.

How many grams is 1 tablespoon of baking soda?

1 tablespoon of baking soda is about 14 g, since 1 tablespoon is 3 teaspoons and USDA lists 4.6 g per teaspoon.

How many grams is half a teaspoon of baking soda?

Half a teaspoon of baking soda is 2.3 g by USDA and 3 g by King Arthur Baking.

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