1/2 Cup Peanut Butter in Grams
1/2 cup of peanut butter weighs 135 g (scooped, King Arthur Baking). Ground peanuts, usually with salt and a little oil. All the figures on this page are approximate conversions based on the King Arthur Baking value, so when a recipe really matters, verify with a kitchen scale. Peanut butter is the ingredient that defeats the measuring cup more thoroughly than any other: it sticks, it traps air, it leaves half of itself behind in the cup, and a half cup of it is the amount a batch of cookies, a satay sauce or a smoothie for a family all need at once.
Why half a cup of peanut butter is a useful amount
Half a cup of peanut butter is the amount that shows up in a batch of peanut butter cookies, a smoothie, a satay sauce or a sandwich spread for a crowd, and it is one of the hardest ingredients to measure in a cup. It sticks to the measure, traps air when you spoon it in, and leaves a different amount behind every time you scrape it out. A level half cup can easily be ten grams off, and in a cookie that is the difference between chewy and dry. Sandwiches, cookies, sauces and satay. The table below is built from the published King Arthur Baking weight for peanut butter measured scooped, so you can weigh it straight into the bowl and skip the sticky cup altogether.
Peanut Butter cups to grams conversion table
| Cups | Grams | Tablespoons (approx.) |
|---|---|---|
| 1/4 cup | 67.5 g | 4.2 g |
| 1/3 cup | 90 g | 5.6 g |
| 1/2 cup | 135 g | 8.4 g |
| 2/3 cup | 180 g | 11.2 g |
| 3/4 cup | 202.5 g | 12.7 g |
| 1 cup | 270 g | 16.9 g |
| 1 1/2 cups | 405 g | 25.3 g |
| 2 cups | 540 g | 33.8 g |
| 3 cups | 810 g | 50.6 g |
| 4 cups | 1080 g | 67.5 g |
The tablespoon column is a bonus for recipes that call for a spoonful or two: one tablespoon of peanut butter weighs about 16.9 g, and one teaspoon about 5.6 g. A cup is 16 tablespoons, so the numbers in the table are just the cup weight divided by 16, rounded to one decimal place. For small amounts a scale that reads to the gram is far more reliable than a spoon, because a heaped tablespoon can weigh half as much again as a level one.
How the weight was measured
Scooped means filling the measuring cup by scooping it through the ingredient, which packs it down more than spooning. That is how peanut butter is normally measured, because it is too thick to spoon loosely, and it is also why the weight can vary: a firmly scooped cup holds more than a lightly scooped one. Weighing removes that variation entirely.
The source for the 270 g figure is King Arthur Baking, and the confidence in the value is high. King Arthur Baking publishes a standard ingredient weight chart that recipe developers use as a reference, and this page follows it exactly rather than averaging across sources, because an average of two different measuring methods is a number that matches nobody's cup.
Worked examples
A batch of peanut butter cookies
A batch of peanut butter cookies calls for 1/2 cup of peanut butter, which is 135 g. The peanut butter has to be weighed straight into the bowl, because a cup measure leaves a thick smear behind and the dough ends up short. Weighing 135 g keeps the cookies chewy rather than dry, and the dough should be chilled before baking so the cookies hold their shape.
A satay sauce for a barbecue
A satay sauce for a barbecue uses 1/2 cup of peanut butter, which is 135 g, whisked with soy sauce, lime, chilli and warm water. The sauce has to be thinned gradually, because peanut butter seizes before it loosens. Weighing 135 g keeps the sauce pourable rather than clumpy, and the sauce can be thinned with more warm water if it tightens as it cools.
A smoothie for a family breakfast
A smoothie for a family of four uses 1/2 cup of peanut butter, which is 135 g, blended with bananas, milk and oats. The peanut butter is the protein and the flavour, so its weight decides whether the smoothie is filling or just sweet. Weighing 135 g keeps the smoothie balanced, and the peanut butter should be added first so the blades can pull it through the fruit.
When this conversion matters most
This conversion matters most when a sticky ingredient has to land in a precise ratio. In a cookie, the weight of peanut butter against the flour decides whether the dough spreads or holds its shape; in a sauce, it decides whether the result pours or clumps; in a smoothie, it decides the calorie count by a wide margin. A cup measure hides all of that behind the residue left in the cup, so two cooks following the same recipe can end up with visibly different results. Weighing the bowl directly is faster than scraping a cup clean, and it is the only way to know the true amount.
Common mistakes with peanut butter
- Scraping a sticky cup clean. A cup measure of peanut butter always leaves some behind, so the amount that reaches the bowl is less than the amount you measured. Weigh the bowl instead and add the peanut butter until the scale reads the right number.
- Measuring a cold, stiff jar. Cold peanut butter is hard to spoon and traps air, so a cup of it weighs less than a cup at room temperature. Let the jar warm up, stir it well, then weigh.
- Forgetting the oil on top. Natural peanut butter separates, and the oil on top is lighter than the solids below. Stir the jar thoroughly before measuring or the first scoop will be mostly oil.
- Guessing for calorie counting. Peanut butter is calorie-dense, so a generous half cup can add hundreds of calories to a recipe. Weighing is the only honest way to track it.
Storage and handling
Cool cupboard; stir natural peanut butter before use. Keeping peanut butter stored properly also keeps its weight per cup stable: an ingredient that has absorbed moisture from the air weighs more per cup than a dry one, so a sealed container is not just about freshness, it is about measurement accuracy too. If a bag has been open for months in a humid kitchen, the first thing to do before a precise bake is to weigh the ingredient rather than trusting the cup.
Frequently asked questions
How many grams is 1/2 cup of peanut butter?
1/2 cup of peanut butter weighs 135 g, measured scooped according to King Arthur Baking. That is the figure to use when converting a recipe from cups to grams, and it is the value the conversion table on this page is built on.
How do I measure peanut butter without a scale?
Scoop the cup through the ingredient and level it off with a knife, which gives the closest result to 135 g per half cup. But scooping is the least consistent method there is: a firm scoop holds far more than a light one. The honest answer is that a scale is the only way to know the exact weight, and for a sticky ingredient like peanut butter it is also faster than scraping a cup clean.
Does peanut butter always weigh the same per cup?
No. Brand, grind, moisture and how settled the container is all shift the weight by a few grams, and for some ingredients the swing can be much larger. The 270 g figure is the standard King Arthur Baking value for peanut butter measured scooped, and it is the right default, but when a recipe is precise, weigh the ingredient and trust the scale over the cup.
Can I use the same conversion for a different brand of peanut butter?
Yes, as a starting point. The 270 g figure is a standard average for peanut butter, and most brands sit within a few grams of it. If you cook with one brand all the time, weigh one cup of it once and note the number on the bag, and you will have a conversion tuned to your own kitchen.
Why does my peanut butter weigh differently every time I measure it?
Because peanut butter is a paste, not a powder or a liquid: it traps air when spooned, sticks to the measure, and changes with temperature. A cold, stiff jar gives a lighter cup than a warm, stirred one, and natural peanut butter separates, so the oil on top is lighter than the solids below. The fix is to stop using the cup: put the bowl on the scale, tare it, and add peanut butter until the scale reads 135 g for a half cup. Stir the jar first, every time.
How should I store peanut butter?
Cool cupboard; stir natural peanut butter before use. Good storage keeps the ingredient fresh and keeps its weight per cup consistent, because moisture absorbed from the air adds grams that the recipe did not ask for.
Related conversions
Use the cups to grams converter, tablespoons to grams converter, weight converter, recipe scaler for instant answers, or browse the cups to grams hub for the full ingredient list. Related pages: Peanut Butter in cups to grams, Almond Flour in cups to grams, Rolled Oats in cups to grams. See also our disclaimer about approximate conversions.