Nuts, Seeds & Butters
Convert cups of peanut butter to ounces
One cup of peanut butter weighs about 9.1 oz, and half a cup comes to roughly 4.55 oz. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 cup of peanut butter =
9.1 oz
- kg
- 0.258
- lb
- 0.569
Peanut Butter: 258 g per US cup · USDA FoodData Central. Natural peanut butter separates. Stir it fully before measuring, or the ratio of oil to solids is off.
Full peanut butter chart →Peanut Butter at a glance
Every number on this page comes from a single figure: 258 grams per US cup (USDA FoodData Central).
- 1 cup
- 258 g
- 1 tablespoon
- 16.1 g
- 1 teaspoon
- 5.38 g
- 1 cup in ounces
- 9.1 oz
- 100 g in cups
- 0.388 cups
- Density
- 1.09 g/ml
cups to ounces chart for peanut butter
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Cups (US) | Grams | Ounces (weight) | Pounds |
|---|---|---|---|
| 1/8 cup | 32.3 g | 1.14 oz | 0.071 lb |
| 1/4 cup | 64.5 g | 2.28 oz | 0.142 lb |
| 1/3 cup | 86 g | 3.03 oz | 0.19 lb |
| 1/2 cup | 129 g | 4.55 oz | 0.284 lb |
| 2/3 cup | 172 g | 6.07 oz | 0.379 lb |
| 3/4 cup | 194 g | 6.83 oz | 0.427 lb |
| 1 cup | 258 g | 9.1 oz | 0.569 lb |
| 1 1/2 cup | 387 g | 13.7 oz | 0.853 lb |
| 2 cup | 516 g | 18.2 oz | 1.14 lb |
| 3 cup | 774 g | 27.3 oz | 1.71 lb |
| 4 cup | 1032 g | 36.4 oz | 2.28 lb |
How this conversion is calculated
Volume-to-weight conversions are only as good as the density behind them. We treat peanut butter as 258 g per US customary cup, which works out to 1.091 g/ml. From there:
- Your cups figure is converted into millilitres or grams using standard unit sizes (cup = 237 ml).
- The density above bridges volume and weight in whichever direction you need.
- The result is rounded the way a cook would round it — to the nearest gram, or to a usable fraction such as 3/8 cups.
Measuring peanut butter accurately
Natural peanut butter separates. Stir it fully before measuring, or the ratio of oil to solids is off.
If a recipe matters to you — bread, macarons, anything with a tight hydration or ratio — weigh it. A £10 digital scale removes the single largest source of variation in home baking, and it is faster than washing three measuring cups.
When cups are fine
- Liquids measured in a proper jug, where volume is the honest unit anyway.
- Forgiving savoury cooking: soups, stews, stir-fries, marinades.
- Small amounts of leaveners and spices, as long as you use level spoons.
Frequently asked questions
How many ounces are in 1 cup of peanut butter?
1 cup of peanut butter is 9.1 oz. This is based on a density of 258 g per US cup.
How many ounces are in 2 cups of peanut butter?
2 cups of peanut butter is 18.2 oz, and 4.55 oz for half a cup.
How much is 100 g of peanut butter in cups?
100 g of peanut butter is about 3/8 cups. Weight is always the more reliable measurement, so use a scale when the recipe gives grams.
Why do other sites give a different number for peanut butter?
Natural peanut butter separates. Stir it fully before measuring, or the ratio of oil to solids is off.
Do UK and Australian cups give the same result?
No. A US customary cup is 236.6 ml, a metric cup used in Australia and New Zealand is 250 ml, and an old UK imperial cup is 284 ml. Our default is the US cup, but you can pick metric cups in the converter.