Inside Skirt vs Top Sirloin — What's the Difference?
Quick Answer
Inside Skirt (inside skirt steak) and Top Sirloin (top sirloin) are not the same cut: Inside Skirt is plate primal (Transversus abdominis muscle — the inner diaphragm muscle); Top Sirloin is sirloin primal (Upper hip, above the sirloin cap (coulotte) and behind the short loin).
Canonical entities: Inside Skirt · Top Sirloin
Side-by-side
| inside skirt | top sirloin | |
|---|---|---|
| Primal | plate | sirloin |
| Muscle / location | Transversus abdominis muscle — the inner diaphragm muscle | Upper hip, above the sirloin cap (coulotte) and behind the short loin |
| Character | The 'other' skirt steak. Thinner, wider, and slightly tougher than the outside skirt (which is the standard 'skirt steak'). Most restaurant fajitas use inside skirt because the outside skirt is exported or sold at premium. Requires high heat, fast cooking, and slicing against the grain. | A large, lean cut from the hip section. The top sirloin butt (NAMP 184) is the main muscle group. Versatile — grilled as steaks, roasted whole, or cut into kabobs. Moderate tenderness with good beefy flavor. Not to be confused with sirloin cap (coulotte/picanha) which sits on top of it. |
Key differences
- Different primals: plate vs sirloin.
- Texture and slicing: compare fibrous, grain-heavy cuts vs more tender steak-style muscles based on each cut’s description.
- Retail naming diverges by country—always map through a canonical cut when translating menus or labels.
When to use each
Inside Skirt
Pick Inside Skirt when you want its specific marbling/texture profile: The 'other' skirt steak. Thinner, wider, and slightly tougher than the outside skirt (which is the standard 'skirt steak'). Most restaurant fajitas use inside skirt because the outside skirt is exported or sold at premium. Requires high heat, fast cooking, and slicing against the grain.
Top Sirloin
Pick Top Sirloin when its primal/muscle traits fit the dish: A large, lean cut from the hip section. The top sirloin butt (NAMP 184) is the main muscle group. Versatile — grilled as steaks, roasted whole, or cut into kabobs. Moderate tenderness with good beefy flavor. Not to be confused with sirloin cap (coulotte/picanha) which sits on top of it.
Inside Skirt and Top Sirloin are different canonical muscles/primals: Inside Skirt is plate (Transversus abdominis muscle — the inner diaphragm muscle); Top Sirloin is sirloin (Upper hip, above the sirloin cap (coulotte) and behind the short loin).
Choose based on tenderness, marbling, grain direction, and how you plan to cook (sear vs braise vs slice thin).
Read the full guides: inside skirt (what-is) · top sirloin (what-is) · inside skirt hub · top sirloin hub