Two tablespoons of peanut butter carry about 7.1 grams of protein. That’s roughly 14 percent of the FDA’s 50 gram Daily Value, and at the $4.97 we paid for a 40 ounce jar in July 2026, that spoonful cost about 14 cents. Peanut butter runs 22.21 grams of protein per 100 grams, which is more than eggs by weight and less than most people assume by the serving.
Both of those things are true at once, and that’s why the question keeps getting answered badly. Here’s the whole jar, priced out.
| Peanut butter portion | Weight | Protein | Fiber | Cost |
|---|---|---|---|---|
| 1 tablespoon | 16 g | 3.6 g | 0.8 g | $0.07 |
| 2 tablespoons | 32 g | 7.1 g | 1.6 g | $0.14 |
| 100 grams | 100 g | 22.2 g | 5.0 g | $0.44 |
| Whole 40 oz jar | 1,134 g | 251.9 g | 56.7 g | $4.97 |
Source: USDA FoodData Central + US store prices, July 2026. Full methodology at /methodology/.
Is peanut butter actually a good source of protein?
Depends entirely on whether you’re asking about the label or the receipt.
By the receipt, it’s excellent. Peanut butter returned 50.7 grams of protein per dollar and finished 10th out of 49 foods in our protein per dollar study. That’s ahead of every single piece of meat, every fish, and every dairy item we priced. Chicken breast managed 24.5. Eggs managed 34.4. The jar beat both of them without trying.
By the spoon, it’s fine but unremarkable. Nobody eats 100 grams of peanut butter in one sitting, or at least nobody admits to it. The realistic serving is two tablespoons, and 7.1 grams of protein is a contribution to a meal, not a meal. Where peanut butter earns its place is as the cheap add-on that pushes an otherwise thin plate over the line.
How much protein is in a whole jar of peanut butter?
About 252 grams, in the 40 ounce jar we priced at $4.97. That’s five times the FDA’s Daily Value for protein sitting in your pantry for less than a fast food combo.
It’s also shelf-stable, which is the quiet part of the value. Nothing in the jar spoils on you, so unlike the sad half-bag of spinach, the protein you bought is the protein you eat. That’s why it made our shelf-stable pantry ranking near the top of the non-legume entries.
The one real caveat is calories. Peanut butter is dense, and 100 grams of it is a lot of food energy for 22 grams of protein. If your goal is grams of protein per calorie rather than grams per dollar, this is not the winner, and nothing about the price changes that.
Are whole peanuts cheaper protein than the jar?
This one goes against instinct. Whole peanuts should be cheaper, because grinding costs money.
They weren’t. Dry roasted peanuts came in at 24.35 grams of protein per 100 grams, which does beat peanut butter’s 22.21 on the nutrition label. But the 16 ounce jar of peanuts ran $2.78, which works out to $0.612 per 100 grams against $0.438 for the peanut butter. The result: peanuts at 39.8 grams of protein per dollar, peanut butter at 50.7.
Almonds do worse still, at 14.8 grams per dollar. We put those two head to head in peanut butter versus almonds, and it isn’t close. If you want nut protein without the price, the big jar of peanut butter is the answer and it isn’t a compromise.
Does peanut butter have fiber?
A bit. USDA data puts it at 5.0 grams of fiber per 100 grams, so those two tablespoons add about 1.6 grams. Call it 6 percent of the 28 gram Daily Value.
That’s real but small. In the fiber per dollar ranking peanut butter landed 30th of 53 at 11.4 grams per dollar, which is fine company but a long way behind whole wheat flour at 77.8. Nobody should be eating peanut butter for fiber. They should be eating it because it makes fiber-heavy food taste better, which is a completely legitimate job.
That’s the actual use case. Peanut butter on whole grain toast with beans and seeds does the flavor work while the bread and the beans do the fiber work. Stirred into no-bake oat and flax energy balls, it binds the whole thing together and adds 7 grams of protein per couple of spoons. Whisked into a peanut sauce for lettuce wraps, it turns a plate of vegetables into something people finish.
How to get more protein out of the jar
Stop treating it as a spread and start using it as an ingredient. Two tablespoons stirred through oatmeal takes a 60 gram bowl from 7.9 grams of protein to about 15, for another 14 cents. That combination is one of the cheapest breakfasts we’ve priced, and it shows up in our breakfast staples ranking for exactly that reason.
The other move is buying the biggest jar the shelf holds. The 40 ounce jar is where the $0.438 per 100 grams comes from, and smaller jars almost always cost more per ounce. That’s the same unit-price habit that saves money across the whole cart, which we go through in how to make grocery shopping cheaper.
Peanut butter isn’t a protein food pretending to be dessert, and it isn’t dessert pretending to be a protein food. It’s a cheap, shelf-stable ingredient that adds about 7 grams of protein for 14 cents every time you reach for it. Reach for it more often. The wider picture of where it fits sits in our high protein on a budget guide.
