Cooking flank steak in the oven at 400°F requires precise timing to avoid turning a tender cut into shoe leather. If you want to know exactly how long to cook flank steak in oven at 400, the short answer is 12 to 16 minutes total, depending on thickness and your target doneness.
Flank steak is lean and fairly thin, so it cooks fast. That is good news when your hungry, but it also means a few extra minutes can ruin the texture. The oven method works best when you use high heat, a hot pan, and a meat thermometer.
How Long To Cook Flank Steak In Oven At 400
At 400°F, a standard flank steak that is about 1 inch thick needs roughly 12 to 16 minutes in the oven. This range assumes you sear it first on the stove. If you skip the sear and roast it straight in the oven, add about 2 to 4 minutes.
Always judge by internal temperature, not just the clock. Carryover cooking will raise the temp another 5°F while the steak rests.
- Rare (120-125°F): 10 to 12 minutes
- Medium rare (130-135°F): 12 to 14 minutes
- Medium (140-145°F): 14 to 16 minutes
- Medium well (150-155°F): 16 to 18 minutes
- Well done (160°F+): 18 to 20 minutes (not recommended)
These times are for a 1-inch thick steak. A thinner flank steak, around 3/4 inch, will cook 2 to 3 minutes faster. A thicker one, closer to 1 1/4 inches, needs 2 to 3 minutes more.
Why Timing Varies So Much
No two flank steaks are the same. Several things change the cook time:
- Thickness of the meat
- Starting temperature (fridge cold vs room temp)
- Whether you sear it first
- Your oven’s real temperature (many run hot or cold)
- The pan or baking sheet you use
Because of this, a thermometer is your best friend here. Guessing leads to overcooked steak, and flank steak does not forgive overcooking.
Step-By-Step Oven Method At 400°F
Follow these steps for a juicy, tender result every time.
- Take the flank steak out of the fridge 20 to 30 minutes before cooking. This helps it cook evenly.
- Pat it very dry with paper towels. Dry meat sears better.
- Season both sides generously with salt and pepper. You can add garlic powder or smoked paprika if you like.
- Preheat your oven to 400°F. Place a cast iron skillet or oven-safe pan inside while it heats.
- Once the oven and pan are hot, carefully put the steak in the pan. It should sizzle right away.
- Sear for 2 minutes per side on the stovetop over high heat. This builds a nice crust.
- Move the whole pan into the oven. Roast for 8 to 12 minutes, depending on thickness and doneness.
- Check the internal temp at the 8-minute mark with a meat thermometer. Pull it 5°F before your target.
- Transfer the steak to a cutting board and let it rest for 5 to 10 minutes.
- Slice against the grain into thin strips. This is the key to tender flank steak.
No-Sear Oven-Only Version
If you don’t want to use the stovetop, you can roast the flank steak directly on a foil-lined baking sheet. Set the oven to 400°F and cook for 14 to 18 minutes, flipping once halfway through.
You won’t get the same crust, but it’s faster and less messy. Just watch the internal temperature closely.
Tips For A Tender Flank Steak
Flank steak is tough if you treat it wrong. Here is how to keep it soft and juicy.
- Do not cook past medium. Medium rare to medium is the sweet spot.
- Always slice against the grain. Look for the lines on the meat and cut across them.
- Let it rest. Cutting too soon lets the juices run out.
- Use a marinade if you have time. Acid and oil help tenderize the surface.
- Don’t overcrowd the pan. Steam is the enemy of a good sear.
A simple marinade of soy sauce, olive oil, garlic, and lime juice works great. Even 30 minutes helps. Overnight is even better.
How To Check Doneness Without A Thermometer
If you don’t own a thermometer, you can use the touch test. Press the center of the steak with your finger.
- Rare feels soft and squishy, like your cheek
- Medium feels springy, like the base of your thumb
- Well done feels firm, like your forehead
This method is not exact, but it gives you a rough idea. A thermometer is still the safer bet, especially at 400°F where things move fast.
Common Mistakes To Avoid
Most people overcook flank steak. Here are the errors that ruin it.
- Leaving it in the oven too long. Set a timer and check early.
- Slicing with the grain. This makes every bite chewy.
- Skipping the rest. Give it at least 5 minutes.
- Using a cold pan. The sear won’t happen and the meat steams.
- Not drying the surface. Wet meat browns poorly.
Another common issue is a oven that runs hot. If your steak is done 3 minutes early, your oven is likely hotter then the dial says. Buy an oven thermometer to check.
Serving Ideas For Oven Flank Steak
Once sliced, flank steak works in many meals. Try these pairings:
- Over a bed of arugula with shaved parmesan
- In warm tortillas with onions and cilantro
- With roasted potatoes and green beans
- On top of a grain bowl with rice and veggies
- In a cold sandwich the next day
Leftovers keep in the fridge for 3 to 4 days. Reheat gently or eat them cold. High heat again will dry it out.
Can You Cook Flank Steak From Frozen At 400°F
Yes, but it takes longer and cooks less evenly. Add about 50 percent more time. For a 1-inch steak, expect 20 to 25 minutes. Sear it first if you can, then roast until it hits your target temp.
For best results, thaw it overnight in the fridge. Frozen steak at 400°F tends to be tough on the outside and underdone in the middle.
Final Timing Cheat Sheet
Here is a quick recap for a 1-inch flank steak at 400°F after a 2-minute-per-side sear:
- Rare: 10 to 12 minutes
- Medium rare: 12 to 14 minutes
- Medium: 14 to 16 minutes
- Medium well: 16 to 18 minutes
Use these numbers as a starting point, then trust your thermometer. Every oven and every steak is a little different. With a bit of practice, you will nail the timing and get a tender, flavorful flank steak every time.