A typical cooked steak contains 25 to 31 grams of protein per 100 grams (about 3.5 ounces), depending on the cut and how much fat it carries. For a more realistic restaurant-sized portion of 8 ounces cooked, you’re looking at roughly 56 to 70 grams of protein, which can cover an entire day’s recommended intake for many adults.
Protein by Cut
Not all steaks are created equal when it comes to protein. Leaner cuts pack more protein per bite because fat takes up space that would otherwise be muscle. Here’s how the most popular cuts compare, based on USDA data for cooked meat per 100 grams:
- Flank steak: 28g protein. This is one of the leanest cuts, so the number stays the same whether you trim the fat or not.
- Top sirloin: 27–30g protein. Lean-only sirloin hits 29–30g, while eating the fat drops it slightly to 27g.
- Tenderloin (filet mignon): 26–29g protein. Trimmed lean comes in around 29g; with fat, closer to 26g.
- Ribeye: 25–31g protein. This cut has the widest range because of its heavy marbling. A well-marbled choice-grade ribeye with fat intact delivers just 25g, but trimmed select-grade ribeye jumps to 31g.
The pattern is straightforward: the more marbling (intramuscular fat) a cut has, the lower its protein density. A ribeye has rich flavor precisely because fat replaces some of the muscle fiber. A flank steak is chewier and leaner, so nearly all its weight is protein-dense muscle.
How Serving Size Changes the Numbers
The 100-gram figures are useful for comparison, but most steaks you’ll actually eat are larger than that. Here’s a quick way to scale up. A 3-ounce cooked serving (roughly the size of a deck of cards) provides about 21 grams of protein from a lean cut. That 3-ounce portion is what most nutrition guidelines consider a single serving, but it’s far smaller than what you’d get at a steakhouse.
A 6-ounce cooked steak, a common portion when cooking at home, delivers around 42 to 51 grams of protein depending on the cut. An 8-ounce cooked steak pushes that to roughly 56 to 68 grams. For context, the recommended daily protein intake for a 155-pound adult is about 56 grams per day, so a single 8-ounce sirloin covers that entirely in one meal.
Keep in mind that raw steak loses about 25% of its weight during cooking as water evaporates. So if you buy a 10-ounce raw steak, it will cook down to roughly 7.5 ounces.
Why Steak Protein Is Especially Useful
Protein quality matters as much as quantity. Beef scores a 92 out of 100 on the PDCAAS scale, which measures how completely your body can digest and use a protein source. That’s on par with soy (91) and far above wheat (42). The score reflects both how well you absorb beef protein (about 98% digestibility) and whether it contains all the essential amino acids your body can’t make on its own. It does.
Beef is particularly rich in leucine, the amino acid that triggers muscle protein synthesis. A single 3-ounce serving of cooked top sirloin provides about 2,050 mg of leucine, while a top round steak delivers closer to 2,400 mg. Research on muscle growth generally points to a threshold of around 2,000 to 3,000 mg of leucine per meal to maximally stimulate muscle repair. Even a modest portion of steak clears that bar.
Fat Grade Affects Protein Density
When you see “Choice” or “Select” on a package, those USDA grades describe how much marbling the beef contains. Choice has more fat than Select, and Prime has the most. This grading directly influences protein content per serving. A select-grade ribeye trimmed of visible fat delivers 31g of protein per 100g, while the same weight of choice-grade ribeye with fat intact drops to 25g. That’s a 20% difference from the same cut of beef.
Interestingly, the actual percentage of protein in the lean muscle tissue itself doesn’t really change as marbling increases. What changes is the ratio: fattier steaks simply contain more fat calories and fewer protein calories per bite. If you’re choosing steak primarily for its protein, a select-grade sirloin or flank steak gives you the most protein per calorie. If flavor is the priority, a choice or prime ribeye will still deliver plenty of protein, just with more fat alongside it.
Comparing Steak to Other Protein Sources
Steak is one of the most protein-dense whole foods available, but it’s worth seeing how it stacks up. A 3-ounce serving of cooked chicken breast has about 26 grams of protein, similar to steak but with less fat. Salmon comes in around 22 grams per 3-ounce cooked serving. A large egg has about 6 grams. To match the protein in a 6-ounce sirloin (roughly 50 grams), you’d need to eat about 8 eggs or nearly two cans of tuna.
Where beef stands out compared to plant proteins is bioavailability. Your body absorbs and uses about 94% of the amino acids in beef, while plant sources like beans and grains are less digestible and often lack one or more essential amino acids. This doesn’t mean plant protein is bad, but you generally need to eat more of it, or combine sources, to get the same usable protein as a serving of steak.