A 3-ounce grilled beef steak has between 20 and 26 grams of protein according to the United States Department of Agriculture. Protein value varies according to the cut and fat content of the beef.
A 3-ounce lean porterhouse steak has 22.16 grams of protein while the same portion of porterhouse marbled with fat only has 20.37 grams. T-bone steak contains similar values. A lean sirloin steak has 26.08 grams of protein; 25.47 grams with fat. Protein values for grass-fed beef are similar to grain-fed beef, however grass-fed beef has much less saturated fat and therefore the protein values for 3 ounces are on the higher end of the scale.