Converter
Why peanut butter needs its own conversion
Peanut Butter weighs about 270g per cup — denser than flour or sugar, closer to how liquids like milk measure. Derived from King Arthur 1/2 cup = 135 g. Smooth; natural/runny varieties vary. A cup is a unit of volume, so ingredients this different in density can't share one generic conversion factor — using a single "1 cup = X g" rule for everything will be wrong for at least some of what you cook.
Common measurement mistakes
- Using a generic cup-to-gram factor for every ingredient — peanut butter does not weigh the same per cup as most other ingredients.
- Measurement note: Derived from King Arthur 1/2 cup = 135 g. Smooth; natural/runny varieties vary.
- Confusing weight ounces with fluid ounces when a recipe lists "oz" — they are not interchangeable.
Frequently asked questions
How many grams are in a cup of peanut butter?
About 270g, derived from King Arthur 1/2 cup = 135 g. Smooth; natural/runny varieties vary.
Does this conversion work for every brand or variety of peanut butter?
It’s a close approximation based on King Arthur Baking. Minor variations in moisture, grain, or brand can shift the exact weight slightly, but this figure works well for everyday cooking and baking.