Sirloin steak is one of the leaner cuts of beef you can buy. A cooked top sirloin (Select grade, trimmed) has about 13 grams of total fat per 100 grams, which qualifies it as a lean cut under USDA labeling standards. That said, the exact fat content varies quite a bit depending on which sirloin cut you choose, how it’s graded, and how much exterior fat gets trimmed before cooking.
What Makes a Cut of Beef “Lean”
The USDA defines a lean cut of beef as one containing less than 10 grams of total fat, 4.5 grams of saturated fat, and 95 milligrams of cholesterol per 100-gram cooked serving. An “extra lean” cut drops those thresholds to under 5 grams total fat and 2 grams saturated fat. By those strict definitions, some sirloin cuts land right at the lean threshold while others sit slightly above it, depending on the grade and how much fat is trimmed.
Compared to fattier steaks like ribeye or T-bone, though, sirloin consistently comes in well below average. A pound of broiled top sirloin (lean only, Select grade) delivers about 771 calories and just 22.5 grams of fat alongside a massive 133 grams of protein. That protein-to-fat ratio is hard to beat among steaks.
Fat Differences Between Sirloin Cuts
The word “sirloin” actually covers several different cuts from the back portion of the cow, and their fat content is not the same. USDA nutrient data for cooked beef (per 100 grams) breaks down like this:
- Top sirloin steak (Select, trimmed to 1/8″ fat): 230 calories, 13 g fat
- Top sirloin steak (Choice, trimmed to 1/8″ fat): 257 calories, 16 g fat
- Tri-tip roast/bottom sirloin (Select, trimmed to 0″ fat): 201 calories, 10 g fat
- Tri-tip roast/bottom sirloin (Choice, trimmed to 0″ fat): 221 calories, 12 g fat
- Sirloin tip round (Select, trimmed to 0″ fat): 181 calories, 8 g fat
- Sirloin tip round (Choice, trimmed to 0″ fat): 196 calories, 9 g fat
The sirloin tip round is the leanest of the group at just 8 to 9 grams of fat, comfortably meeting the USDA “lean” definition. Bottom sirloin (tri-tip) falls in the middle. Top sirloin steak, the cut most people think of when they hear “sirloin,” is the fattiest of the three, especially at Choice grade with some external fat left on. If you’re specifically trying to minimize fat, look for sirloin tip or ask your butcher to trim the exterior fat closely.
How USDA Grade Changes the Fat
The grade stamped on your steak reflects how much marbling (intramuscular fat) runs through the meat. Prime beef comes from well-fed young cattle and has the most marbling. Choice has less, and Select is leaner still, though it trades some juiciness and flavor for that lower fat count.
The numbers above show the practical difference: choosing Select over Choice top sirloin saves you about 3 grams of fat and 27 calories per 100-gram serving. That gap is modest for a single meal, but it adds up if you eat steak regularly. Most grocery stores carry Choice and Select. Prime sirloin, with its higher marbling, is typically found at specialty butchers or upscale restaurants and will push the fat content higher than any of the figures listed above.
How Sirloin Compares to Other Steaks
Within the lineup of popular steak cuts, sirloin sits on the leaner end. Ribeye steaks typically contain 18 to 22 grams of fat per 100 grams cooked, and a T-bone or porterhouse can run even higher because of the strip loin portion. Tenderloin (filet mignon) is comparable to top sirloin in fat, sometimes slightly lower. Flank steak and eye of round are among the leanest options at around 7 to 10 grams, putting them in the same range as sirloin tip.
If your priority is keeping fat low while still eating a recognizable “steak,” sirloin hits a practical sweet spot. It’s lean enough to fit comfortably into a fat-conscious diet, yet it has enough intramuscular fat to hold flavor when grilled or broiled.
Protein and Nutrient Density
The real strength of sirloin is its protein density. That pound of broiled lean top sirloin packs 133 grams of protein, making it one of the most concentrated whole-food protein sources available. A typical 3-ounce (85-gram) serving gives you roughly 26 grams of protein for only about 180 to 220 calories depending on the cut and grade.
Sirloin also delivers iron, zinc, and vitamin B12 in amounts that are difficult to match with poultry or plant foods. A single serving provides a meaningful portion of your daily needs for all three nutrients. Iron from beef is in the heme form, which your body absorbs more efficiently than the non-heme iron found in beans or spinach. For people managing iron levels or building muscle, sirloin’s nutrient profile per calorie is notably efficient.
Keeping It Lean When You Cook
How you prepare sirloin matters as much as the cut itself. Trimming visible exterior fat before cooking removes a significant amount of total fat, sometimes dropping a serving by 3 to 5 grams. Broiling, grilling, or pan-searing on a rack allows rendered fat to drip away from the meat. Adding butter or oil to the pan, basting with fat, or finishing with a cream-based sauce can easily double the fat content of the finished plate.
Portion size also plays a role. A restaurant sirloin often weighs 8 to 12 ounces, which is two to three times the 3-ounce serving used in nutrition data. Sticking closer to a palm-sized portion keeps the calorie and fat numbers in the lean range. The American Heart Association’s 2026 dietary guidance recommends choosing lean, unprocessed cuts when eating red meat and limiting both portion size and how often you eat it as part of a heart-healthy pattern.