Skirt Steak vs Flank Steak: A Butcher Breaks Down the Differences

Skirt steak and flank steak get confused constantly — and I understand why. They're both long, flat, relatively lean cuts that are popular for fajitas, stir-fry, and slicing against the grain. But they come from completely different parts of the animal and have genuinely different characteristics.

After 40 years of cutting and selling both, here's the real breakdown.

Where They Come From

Skirt Steak

Skirt steak is the diaphragm muscle — the muscle that separates the chest cavity from the abdominal cavity. There are actually two skirt steaks per animal:

• Outside skirt (diaphragm): Thicker, more marbled, more tender, more flavorful. This is the superior cut. Most outside skirt gets exported to Japan or goes to restaurants, which is why you rarely see it at retail.
• Inside skirt (transversus abdominis): Thinner, tougher, less marbled. This is what you usually find at the grocery store labeled simply "skirt steak."

Both come from the plate primal area.

Flank Steak

Flank steak is the abdominal muscle from the flank primal — the lower belly area behind the plate. It's a single, flat muscle (the obliquus internus abdominis) with long, clearly visible fibers running lengthwise. There's one per side of the animal.

The Key Differences

Factor	Skirt Steak	Flank Steak
Location	Diaphragm (plate area)	Abdominal wall (flank)
Shape	Long, narrow ribbon (20-24" long, 3-4" wide)	Wider, flatter oval (12-14" long, 5-7" wide)
Thickness	Thinner (outside: 3/4"; inside: 1/2")	Thicker (1-1.5")
Grain	Runs crosswise (across the short dimension)	Runs lengthwise (along the long dimension)
Marbling	More (especially outside skirt)	Less — quite lean
Flavor intensity	Very high — rich, beefy, almost buttery	High — clean, intense beef flavor
Tenderness	More tender (with proper slicing)	Slightly tougher (needs thin slicing)
Weight	1-1.5 lbs per steak	1.5-2.5 lbs per steak
Price (2026)	$12-$18/lb	$10-$14/lb

The Grain Direction Matters

This is the critical detail most people miss. The grain runs in different directions on these two cuts, and it affects how you slice them:

• Skirt steak: The grain runs across the narrow width. So you slice lengthwise — along the long dimension — cutting across those short fibers. Some people cut the long skirt into shorter segments first, then slice each segment against the grain.
• Flank steak: The grain runs along the length. You slice across the short dimension — perpendicular to the long direction of the steak — to cut through the fibers.

Both must be sliced thin and against the grain. Mess this up and even a perfectly cooked steak will be chewy.

Cooking Methods

Skirt Steak

Skirt steak demands extreme heat and very short cooking times. The thinness means it goes from perfect to overcooked in seconds.

• Blazing hot grill or cast iron — the hottest you can get
• 2-3 minutes per side for outside skirt; 1.5-2 minutes for inside skirt
• Target: medium-rare (130°F). Don't go past medium.
• Rest 5 minutes, slice against the grain

Flank Steak

Flank is more forgiving due to its thickness but still benefits from high heat.

• Hot grill or cast iron
• 4-5 minutes per side for a standard 1.25" thick flank
• Target: medium-rare to medium (130-140°F). Don't go past medium.
• Rest 8-10 minutes, slice thin against the grain

Best Uses

Choose Skirt Steak For:

• Fajitas: The classic choice. The loose grain absorbs seasonings and charred flavor beautifully.
• Carne asada: Outside skirt is the authentic choice for Mexican grilled meat preparations.
• Korean BBQ: Thinly sliced skirt is excellent for bulgogi and similar preparations.
• Quick weeknight meals: The fast cook time (under 5 minutes) makes it ideal for speed.

Choose Flank Steak For:

• London broil: The traditional cut for this preparation (broiled or grilled whole, sliced thin).
• Stir-fry: The uniform thickness slices neatly into consistent strips.
• Stuffed and rolled (braciole/roulade): The wide, flat shape is perfect for stuffing, rolling, and braising.
• Feeding a crowd: A single 2 lb flank serves 4-5 people when sliced.

The Marinade Question

Both cuts take well to marinades, but neither requires one — the beef flavor is strong enough to stand on its own with just salt and pepper.

If you do marinate:

• Acid-based marinades (lime, vinegar) should be limited to 2-4 hours. Longer and the acid denatures the surface proteins, creating a mushy texture.
• Oil-and-herb marinades can go longer (4-12 hours) without negative effects.
• Always pat dry before cooking — surface moisture prevents the Maillard reaction and you'll steam instead of sear.

The Availability Problem

Flank steak is widely available at any grocery store. Skirt steak — particularly the superior outside skirt — is harder to find because:

1. A large percentage of US outside skirt is exported to Japan, where it commands premium prices.
2. Restaurants buy much of the remaining supply for fajita programs.
3. What reaches retail is often inside skirt (the thinner, tougher variety).

If your butcher carries outside skirt, buy it. If you can only find inside skirt at the grocery store, know that it's still a good cut — just thinner and slightly less tender than the outside version. Ask your butcher to source outside skirt for you — many can get it on special order.

My Verdict

If I could only have one: outside skirt steak. The flavor is unmatched, the cook time is lightning fast, and when sliced properly, the tenderness is fantastic. But I'd need flank in my rotation too — it's more versatile, feeds more people per steak, and the wider surface area makes it better for certain preparations.

Know the difference, choose based on your meal plan, and always — always — slice thin against the grain. For even more flavor, try wagyu skirt or flank steak from The Meatery — the marbling in wagyu versions of these cuts is a game-changer.