How much protein in sirloin steak can come down to a few different things, how many grams the steak is in weight, what cut it is, so this means the quality of the sirloin steak and lastly the way you cook or how well cooked your steak is.
Beef in general terms has a good high amount of protein in it as I have written about before and also has many benefits if added into your daily diet in some meals throughout the week.
Not only can you get protein from eating sirloin steak you get good fats and many vitamins and minerals too which one of the important ones is iron.