Same bean. Different amount of water, and a very different price per gram. Dry black beans carry 21.6 grams of protein per 100 grams against 6.0 grams for the canned version, and they return 81.0 grams of protein per dollar against 30.1 for the can.
Both of those gaps are real. Only one of them means what people think it means.
| Bean | Form | Protein / 100 g | Fiber / 100 g | Protein per $1 | Fiber per $1 |
|---|---|---|---|---|---|
| Pinto beans | Dry | 21.4 g | 15.5 g | 97.9 g | 70.8 g |
| Black beans | Dry | 21.6 g | 15.5 g | 81.0 g | 58.1 g |
| Black beans | Canned | 6.0 g | 5.6 g | 30.1 g | 27.9 g |
| Chickpeas | Dry | 20.5 g | 12.2 g | 56.7 g | 33.8 g |
| Chickpeas | Canned | 4.9 g | 4.8 g | 22.0 g | 21.5 g |
| Kidney beans | Canned | 5.2 g | 4.3 g | 23.4 g | 19.3 g |
Source: USDA FoodData Central + US store prices, July 2026. Full methodology at /methodology/.
Why the per 100 gram column is the wrong comparison
Look at that table and canned beans appear to be a nutritional disaster. They aren’t. You’re comparing a food with the water taken out against the same food with water put back in and then packed in more of it.
A dry bean is a bean minus its water. A canned bean has been soaked, cooked, and sealed in liquid, and our figures use the full 439 gram net weight of the can including that liquid. Of course 100 grams of one has more protein than 100 grams of the other. You’d get the same effect comparing 100 grams of raisins to 100 grams of grapes and concluding grapes are a scam.
The columns that actually mean something are the last two, because a dollar is a dollar whichever form you buy.
How many dried beans equal a can?
We’re not going to tell you, and the reason is worth spelling out.
Run the conversion on protein and you get one answer: a can of black beans holds about 26.5 grams of protein, and matching that from the dry bag takes roughly 123 grams of dry beans. Run the same conversion on fiber and you get a different answer: the can holds about 24.6 grams of fiber, and matching that takes roughly 159 grams of dry beans.
Those two answers disagree by about 30 percent. That’s your signal that we hold no reliable dry to cooked yield ratio, only nutrient content and prices, and that a clean sounding conversion built out of our numbers would be fiction. Plenty of sites will hand you a confident cup measurement. We priced groceries and read labels, so we’ll stay in our lane and say the bag’s own instructions are a better guide than we are.
Do you lose anything by buying the can?
On protein and fiber, only what the water dilutes and whatever goes down the sink when you rinse. That’s it.
The part we cannot speak to is everything else. We hold no vitamin data, no mineral data, no iron figures. If somebody tells you canned beans lose a specific percentage of some nutrient, they read that somewhere we didn’t, and USDA FoodData Central is where you’d go to check it rather than here.
The one real trade with cans is sodium, since most are packed with salt added. Rinsing removes some of it, and no salt added cans exist on the same shelf for about the same money. We didn’t audit sodium, so that’s guidance rather than data.
Which is better value, canned or dried?
The bag, by roughly 2.7 times on protein. Dry black beans returned 81.0 grams per dollar and the can returned 30.1. Dry chickpeas returned 56.7 against 22.0 canned. On fiber the pattern holds: dry pinto led everything we priced at 70.8 grams per dollar, and canned black beans came in at 27.9.
Dry pinto beans sit at the top of both our protein per dollar ranking and near the top of the fiber per dollar ranking, which is a rare double. We wrote that pattern up properly in beans win twice, and the cost side alone is in canned versus dry beans.
A note on what’s missing from the table. We priced canned kidney beans but not dry kidney beans, and we priced dry pinto, navy, lentils, and split peas but not their canned versions. So the head to head pairs are black beans and chickpeas. Everything else in that table is a single form, and we’re not filling the blanks by guessing.
Which should you actually buy?
Both, for different jobs.
Bags for the cooking you plan. A 4 pound bag of pinto beans at $3.97 is the best protein value in the entire store and it feeds you for weeks, as long as you have somewhere to keep it. We covered that in how long dried beans last, and the sequence for getting a good pot out of it is in how to cook dried beans from scratch.
Cans for the cooking you don’t. At 88 cents, a can that needs no soak and no cooking at all is still cheaper protein than almost anything else in the building. It only looks expensive standing next to the bag.
My cupboard runs about four cans and one big bag at any time, and I’ve stopped feeling clever about it. The dry beans win on paper. The cans win on Tuesdays.
