A typical 1 cake serving of rice cakes contains 0.7 grams of protein (8.2 g per 100 g), which makes it only a minor source of protein. That covers roughly 1% of the 50 g reference Daily Value, so it adds toward your protein total for the day.
Only about 8% of the calories in rice cakes come from protein, so it is more of an energy food than a protein food. It is worth eating for other reasons; the protein it adds to a day is incidental.
Among the 111 grains in the database, rice cakes ranks 111th by protein per serving, and 759th out of all 796 foods on the site. Set against corn tortilla, another grain entry in the database, a serving carries about 0.7 g less protein (corn tortilla has 1.4 g per 1 tortilla).
It is an incomplete protein on its own; pairing it with other plant foods across the day covers the full range of essential amino acids. The serving above is counted by piece at 9 g. Because pieces vary, the per-100 g figure is the one to use when comparing this against a food measured a different way.
Source: USDA FoodData Central #170250 - "Snacks, rice cakes, brown rice, plain, unsalted" (SR Legacy, published 4/1/2019). Values are the published reference figures for that record, not lab measurements for a specific brand or batch.
Quick answers
Rice cakes protein FAQ
How much protein is in rice cakes per 100 g?
Rice cakes has 8.2 g of protein per 100 g. A typical 1 cake serving (9 g) provides 0.7 g.
Is rice cakes a complete protein?
No. Rice cakes is an incomplete protein on its own; pairing it with other protein sources across the day covers the full range of essential amino acids.
How much of the Daily Value does a serving of rice cakes cover?
A 1 cake serving of rice cakes contains 0.7 g of protein, about 1% of the 50 g reference Daily Value.
Is rice cakes a good source of protein?
Rice cakes is only a minor source of protein, and about 8% of its calories come from protein, which makes it more of an energy food than a protein food. Set against corn tortilla, another grain entry in the database, a serving carries about 0.7 g less protein (corn tortilla has 1.4 g per 1 tortilla).