Which is cheaper for protein, lentils (cooked) or soybeans (dried, raw)?

Soybeans (dried, raw), at $0.010 per gram of protein against $0.022 for lentils (cooked) (July 2026 US grocery prices). A 30 g protein serving costs $0.29 vs $0.67.

Which has more protein per calorie, lentils (cooked) or soybeans (dried, raw)?

Soybeans (dried, raw), with 8.2 g protein per 100 kcal against 7.8 g for lentils (cooked), 1.1x leaner. That matters when you are cutting and calories are the binding constraint.

Which should I buy, lentils (cooked) or soybeans (dried, raw)?

Soybeans (dried, raw) wins on both axes here: cheaper per gram of protein and more protein per calorie. Unless taste, prep or the rest of your macros say otherwise, it is the better default.

Protein head-to-heads · July 2026

Lentils (cooked) vs Soybeans (dried, raw): which protein is cheaper?

USDA macros joined to current US grocery prices, reduced to the two numbers that decide it: dollars per gram of protein, and protein per calorie.

Soybeans (dried, raw) is 2.3x cheaper per gram of protein ($0.010/g vs $0.022/g), while it also carries more protein per calorie (8.2 g vs 7.8 g per 100 kcal), so it wins on both axes.

Food	$/g protein	30 g protein costs	You need	kcal that come with it	Protein/100 kcal
Lentils (cooked)	$0.022	$0.67	333 g	387 kcal	7.8 g
Soybeans (dried, raw)	$0.010	$0.29	82 g	367 kcal	8.2 g

Full macros, per serving

Food (per serving)	Price	kcal	Protein	Carbs	Fat
Lentils (cooked) (100 g)	$0.20	116	9 g	20 g	0.4 g
Soybeans (dried, raw) (100 g)	$0.35	447	36.5 g	30.2 g	19.9 g

A week of protein from each

Hitting a common 100 g/day protein target from soybeans (dried, raw) alone costs $6.71 a week; from lentils (cooked) alone, $15.56. That is a gap of $8.84 every week for the same protein. In practice you mix sources: the planner computes the cheapest mix for your exact target and calorie cap, live from the same dataset.

This one is not a trade-off

Soybeans (dried, raw) is both the cheaper protein ($0.010/g against $0.022/g) and the leaner one (8.2 g protein per 100 kcal against 7.8 g). Most matchups force you to pick a side. This one does not, so lentils (cooked) has to win on taste, prep time or what else it brings to the meal, because it is not winning on the numbers.

The amount you actually have to eat

Thirty grams of protein means 333 g of lentils (cooked), against 82 g for soybeans (dried, raw). That is a real constraint, not a footnote: a price per gram only counts if the serving is one a person will finish. Treat lentils (cooked) as the base of a meal that other protein is added to, not as the protein itself.

Two budget staples, so the tiebreak is elsewhere

Both of these sit in the cheapest third of everything we track (#8 and #2 of 25), and the difference between them is $0.38 per 30 g of protein. That is small enough that shelf life, prep time and whether you will actually eat it should decide this, not the price column.

Compare against other foods

Frequently asked

Which is cheaper for protein, lentils (cooked) or soybeans (dried, raw)?: Soybeans (dried, raw), at $0.010 per gram of protein against $0.022 for lentils (cooked) (July 2026 US grocery prices). A 30 g protein serving costs $0.29 vs $0.67.
Which has more protein per calorie, lentils (cooked) or soybeans (dried, raw)?: Soybeans (dried, raw), with 8.2 g protein per 100 kcal against 7.8 g for lentils (cooked), 1.1x leaner. That matters when you are cutting and calories are the binding constraint.
Which should I buy, lentils (cooked) or soybeans (dried, raw)?: Soybeans (dried, raw) wins on both axes here: cheaper per gram of protein and more protein per calorie. Unless taste, prep or the rest of your macros say otherwise, it is the better default.

Prices are representative US grocery prices as of July 2026; your store will differ. Educational content, not medical or dietary advice. Dataset: free download, CC-BY.