WellByNumbers.

Kidney beans (cooked) vs Black beans (cooked)

Both count toward 30 plants a week.

Kidney beans (cooked)Black beans (cooked)
Protein · per 100 g8.7 g8.9 g
Carbs · per 100 g22.8 g23.7 g
Fat · per 100 g0.5 g0.5 g
Fiber · per 100 g7.4 g8.7 g
Energy · per 100 g127.0 kcal132.0 kcal
Protein · per 100 kcal6.8 g6.7 g
To hit 30 g protein346 g · 439 kcal339 g · 447 kcal

The same three numbers, drawn

Protein / 100 g8.78.9Fiber / 100 g7.48.7Protein / 100 kcal6.86.7Kidney beansBlack beans

What 30 g of protein looks like on a plate

346 gKidney beans439 kcal rides along339 gBlack beans447 kcal rides alongsquare area drawn to scale · grams needed for 30 g protein

Where the calories come from

protein 27%carbs 70%3%
protein 26%carbs 70%4%

The one-line verdict: Kidney beans (cooked) delivers 1.0× the protein per calorie of Black beans (cooked) (6.8 g vs 6.7 g per 100 kcal).

More protein / 100 g: Black beansMore fiber / 100 g: Black beansLighter per 100 g: Kidney beansSmaller 30 g portion: Black beans

Swap in your own pair

Bold marks the better side of each row. "Per 100 kcal" answers the density question — which food delivers more protein for the energy it costs. Portion row is computed live from the same USDA base values shown on each food page.