The cheapest legume and grain pair in our ranking is dry pinto beans plus whole wheat flour, at 97.0 grams of protein per dollar when you split the dollar 50/50 between them. Rice and beans, the combo with all the folklore, is real too, it’s just not the winner: pintos with brown rice land at 67.2.
First, the framing, stated carefully. Legumes and grains complement each other’s amino acid profiles, which is why the pairing has been dinner in kitchens all over the world for a very long time, and why it gets called a complete protein. We’re not here to litigate the biology. We’re here to price it. We took the legumes and grains from our protein per dollar study and scored 20 pairs the same way: spend 50 cents on the legume, 50 cents on the grain, count the protein grams that dollar buys.
| Rank | Pair | Protein per $1 (50/50 split) |
|---|---|---|
| 1 | Pinto beans (dry) + Whole wheat flour | 97.0 g |
| 2 | Black beans (dry) + Whole wheat flour | 88.5 g |
| 3 | Brown lentils (dry) + Whole wheat flour | 86.8 g |
| 4 | Navy beans (dry) + Whole wheat flour | 86.0 g |
| 5 | Green split peas (dry) + Whole wheat flour | 85.0 g |
| 6 | Pinto beans (dry) + Old-fashioned rolled oats | 72.2 g |
| 7 | Pinto beans (dry) + Brown rice (dry) | 67.2 g |
| 8 | Pinto beans (dry) + Pearled barley (dry) | 67.1 g |
| 9 | Black beans (dry) + Old-fashioned rolled oats | 63.8 g |
| 10 | Brown lentils (dry) + Old-fashioned rolled oats | 62.2 g |
Source: USDA FoodData Central + single-store prices, July 2026. Full methodology at /methodology/.
What does a 50/50 dollar split actually mean?
Every pair is scored as if you handed the cashier one dollar and spent exactly half on each food. Pinto beans deliver 97.9 grams of protein per dollar on their own, so 50 cents of pintos brings 49-ish grams to the party; 50 cents of brown rice, which scores 36.6 per dollar solo, brings its half. Add the two halves and you get the pair’s number.
It’s a deliberately boring method. No serving-size games, no assumptions about your recipe ratios, just an even split so no single cheap ingredient can carry the score.
Why does whole wheat flour keep winning these rankings?
Because at 96.0 grams of protein per dollar, flour nearly matches the pinto beans themselves at 97.9. Every other grain dilutes the beans: oats score 46.6 on their own, brown rice 36.6, pearled barley 36.3. Pair pintos with rice and the combo drops to 67.2. Pair them with flour and you barely lose anything, 97.0.
The catch is the same one from our other studies: flour is an ingredient, not dinner. The flour pairs only pay off if you bake, which is less exotic than it sounds. Beans plus homemade bread, beans plus tortillas, lentils plus flatbread. Humanity ran on that menu for a very long time, and at these prices you can see why.
Which pair should you actually cook?
The one that becomes a meal you’ll repeat. Beans and rice is the obvious starting point, 67.2 grams of protein per dollar in its pinto-and-brown-rice form, and it doesn’t need a motivational speech. Lentils with rice is the speed play, since lentils skip the soak entirely: a one-pot dal over rice is the weeknight version of this whole article. And if you want the batch-cooking angle, 20 minute bean and rice meals is the same math wearing a meal-prep container.
Here’s the part I find genuinely freeing: the spread between the best pair and the worst pair is only 1.8x. Green split peas with pearled barley, the last-place finisher, still delivers 55.1 grams of protein per dollar. Even the loser of this ranking buys more than the FDA’s 50 gram protein Daily Value with a single dollar. You cannot meaningfully mess this up.
How did we calculate the pairs?
Protein values come from USDA FoodData Central and prices are July 2026 US figures from audited Walmart national listings, all pulled from our full protein per dollar ranking. We limited the pool to dried legumes and whole grains, scored every legume-grain combination on the 50/50 dollar split, and kept the 20 pairs. The FDA’s 50 gram Daily Value is a labeling benchmark rather than a personal target, but it’s a useful yardstick when every pair on the list clears it with one dollar.
If you’re building actual meals out of this, the high protein on a budget guide is the full playbook, and what 50 grams of protein costs per day prices out the daily version. The short answer stays the same either way: buy a bag of beans, buy a bag of something grainy, and let two of the cheapest foods in the store cover for each other.
