Sirloin Steak (Top Sirloin) vs Flank Steak
Compare sirloin steak (top sirloin) and flank steak side by side for calories, protein, fat, iron, zinc, vitamin B12, cooking methods, and reference price per pound. All values use the shared per 100g raw reference system for nutrition logging and meal planning.
| Nutrient | Sirloin Steak (Top Sirloin) | Flank Steak | Diff |
|---|---|---|---|
| Calories | 183 kcal | 164 kcal | 19 kcal |
| Protein | 27g | 20.1g | +6.9g |
| Total Fat | 7.6g | 9.4g | +-1.8g |
| Saturated Fat | 2.9g | 3.5g | +-0.6g |
| Carbohydrates | 0g | 0g | — |
| Cholesterol | 68mg | 57.7mg | 10.3mg |
| Iron | 1.8mg | 1.8mg | — |
| Zinc | 5mg | 5.6mg | -0.6mg |
| Vitamin B12 | 1.4µg | 1.2µg | +0.2µg |
| Niacin (B3) | 8mg | 6.8mg | +1.2mg |
| Selenium | 28.0µg | 23.3µg | +4.7µg |
| Potassium | 350mg | 331.8mg | +18.2mg |
Sirloin Steak (Top Sirloin)
Lean, flavorful steak with less marbling than premium cuts. Great balance of tenderness and beef flavor at a moderate price point.
Flank Steak
Lean, flavorful cut from the abdominal muscles. Best when marinated and sliced against the grain. Popular for fajitas and stir-fries.
Price comparison
Cut characteristics at a glance
Culinary and texture notes for planning — not a ranking of which cut is better.
| Trait | Sirloin Steak (Top Sirloin) | Flank Steak |
|---|---|---|
| Primal source | Loin (top sirloin) | Flank (abdominal muscle) |
| Typical tenderness | Moderate — more forgiving for classic steak plates | Lower unless sliced thin against the grain |
| Muscle grain | Finer, more steak-like | Long, pronounced fibers |
| Marbling | Small (Choice reference) | Slight |
| Ideal doneness | Medium rare to medium | Rare to medium rare |
| Common cooking methods | Grill, pan-sear, broil, stir-fry strips | Grill, broil, stir-fry; often marinated first |
| Typical recipe uses | Grilled steak, steak salad, fajita strips | London broil, fajitas, stir-fry, sliced salads |
| Reference price | ~$9.99/lb planning estimate | ~$8.99/lb planning estimate |
Practical differences
Where each cut comes from
Top sirloin comes from the loin primal — a section that supports less constant movement, which generally means a more steak-friendly texture. Flank comes from the abdominal muscles on the flank primal, where longer fibers and more work give the cut a distinct grain and chew when not sliced correctly.
Texture and grain
Sirloin usually slices cleanly for a classic steak plate. Flank has a visible long grain and benefits from slicing against it after a quick high-heat cook. Overcooking flank tends to amplify toughness more than it does with sirloin.
Flavor profile
Both cuts carry solid beef flavor. Sirloin offers a balanced, everyday steak character with moderate marbling. Flank is often described as beefy and works well with marinades because the surface area and grain accept seasoning readily.
Nutrition snapshot (per 100g raw)
In this site’s reference system, sirloin shows higher protein (27.0 g vs 20.1 g) and higher calories (183 vs 164 kcal), while also showing lower total fat (7.6 g vs 9.4 g) than flank. Flank is sometimes called a “lean muscle” in butcher language, but total fat grams on the label reference can differ — always compare the numbers you are logging.
Grilling and cooking fit
Both cuts work on a hot grill. Sirloin is a common choice for straightforward steak grilling to medium-rare or medium. Flank is usually cooked quickly over high heat, rested, and sliced thin — marinating first is a common approach for texture and flavor, not a requirement.
When to pick which
Choose sirloin when you want a classic grilled steak with more protein per 100g raw and a more forgiving texture window. Choose flank when you plan to slice for tacos, salads, or stir-fry and want a flat cut that takes well to marinades. Neither is universally better — the fit depends on your recipe and portion-logging needs.
Frequently asked questions
What is the difference between sirloin and flank steak?
Sirloin comes from the loin primal and is typically more tender for a classic steak plate. Flank comes from the abdominal muscles, has a pronounced grain, and is usually sliced thin against the grain after cooking. Nutrition and price differ as shown in the comparison table above.
Which cut has more protein?
Top sirloin shows more protein per 100 grams raw in this reference system — about 27.0 g for sirloin versus about 20.1 g for flank.
Which cut is leaner on total fat?
Sirloin shows less total fat per 100 grams raw here — about 7.6 g versus about 9.4 g for flank. That differs from casual “lean steak” language; compare the label or reference numbers you are actually logging.
Which is more tender?
Sirloin is generally more tender for whole-steak serving. Flank can be tender when cooked quickly to rare or medium-rare and sliced thin against the grain.
Which cut suits grilling?
Both work on a grill with different techniques. Sirloin suits classic grilled steaks. Flank suits quick high-heat grilling followed by thin slicing; marinating is a common prep step for flank.
Can sirloin and flank be substituted in recipes?
Sometimes. For whole grilled steaks, sirloin is the closer match. For sliced fajitas, stir-fry, or salad strips, flank is the traditional choice — but sirloin strips can work if sliced and cooked carefully.
Do cooking methods change nutrition values?
Cooking changes weight and how nutrients are concentrated per gram of finished meat. Raw reference tables stay on per 100g raw; for cooked portions use the raw vs cooked beef weight converter or cut-specific nutrition tools.
Data source
Nutrition values are from the shared per 100g raw reference system maintained from USDA FoodData Central source records. Price values are general planning estimates, not live store quotes. This comparison is for informational nutrition logging and meal planning use only. It is not medical guidance. Values are per 100g raw reference data from USDA FoodData Central source records unless noted. Flank primary macros follow USDA FDC 2646175 (Foundation). Flank vitamin B12, niacin, vitamin B6, and selenium use SR Legacy FDC 169433 where the Foundation record omits those fields. Sirloin values use the site top-sirloin raw reference used across sirloin tools on this site.
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