How Long To Cook London Broil In Oven At 400 | Nail The Cut

At 400°F, most London broil cuts finish in 18–28 minutes, then rest 8–12 minutes, depending on thickness and the doneness you want.

London broil is one of those names that can trip people up. It’s not a single cut. It’s a cooking method that’s often sold as a lean, broad steak like top round or flank. In the oven, the win is simple: steady heat, good browning, and a predictable finish—if you treat time as a range, not a promise.

You’re here for clean timing at 400°F, not vague cooking talk. Below you’ll get time ranges that work, pull temperatures that match doneness, and small moves that keep a lean steak tender. You’ll also see a broil finish option for a darker crust, plus a one-page checklist you can save.

What Changes Oven Time At 400°F

If you’ve ever followed a single “cook X minutes” rule and ended up with a dry, gray slab, you already know the trap. London broil needs a few inputs before you can trust a timer.

Thickness Beats Weight

Oven time tracks thickness more than total weight. A wide steak that’s 1 inch thick cooks faster than a smaller steak that’s 1½ inches thick. Measure the thickest point with a ruler or the marks on your knife.

Starting Temperature Sets The Pace

A steak straight from the fridge takes longer than one that sits out briefly. If you let the meat sit 20–30 minutes, expect the shorter end of the time range.

Your Pan And Rack Matter

A preheated cast-iron skillet pushes heat into the meat faster than a cold sheet pan. A rack also helps. It lifts the steak so hot air can move around it, which improves browning and keeps the bottom from steaming.

Doneness Is A Temperature, Not A Color

Lean cuts turn tough fast once they cross into well-done territory. A thermometer takes the guesswork out. You’ll pull the steak early, then let carryover heat finish the job while it rests.

Best Method For London Broil At 400°F

You have two solid options: bake only, or sear first. Bake-only is simpler and still tasty. Sear-first gives you a richer crust. Both work as long as you track internal temperature and let the meat rest.

Step-By-Step: Sear Then Oven

1. Heat the oven and pan. Set the oven to 400°F. Put a cast-iron skillet in the oven while it heats, 10–15 minutes.
2. Pat dry and season. Blot both sides with paper towels. Season with kosher salt, black pepper, garlic powder, and a little smoked paprika. Add a light brush of oil.
3. Sear fast. Carefully move the hot skillet to the stove over medium-high heat. Lay the steak in and sear 60–90 seconds per side.
4. Finish in the oven. Slide the skillet back into the oven and start timing.
5. Check early. Start checking internal temperature a few minutes before the low end of the range for your thickness.
6. Rest, then slice. Rest 8–12 minutes. Slice thin across the grain.

Step-By-Step: Bake Only On A Rack

1. Heat the oven. Set it to 400°F.
2. Set up the pan. Place a wire rack on a rimmed sheet pan. Lightly oil the rack.
3. Season. Pat dry, then season as above.
4. Bake and check. Bake, then check temperature early. Flip once halfway if you’re baking directly on a pan without a rack.
5. Rest and slice. Rest before slicing across the grain.

Oven Time Chart For London Broil At 400°F

Use the chart as a starting point. Your steak can run faster or slower based on pan type, starting temperature, and how evenly your oven holds 400°F. A thermometer is the final call.

Target internal temperatures in this article match common doneness ranges. Food safety rules also matter. The USDA’s beef guidance lists 145°F with a rest time as the safe minimum for steaks and roasts, so plan around your household and who’s eating. USDA FSIS safe temperature chart spells out the baseline.

Thickness	Pull Temperature	Time At 400°F
1 inch	120–125°F (rare)	14–18 minutes
1 inch	130–135°F (medium-rare)	18–22 minutes
1 inch	140–145°F (medium)	22–26 minutes
1¼ inch	120–125°F (rare)	16–20 minutes
1¼ inch	130–135°F (medium-rare)	20–25 minutes
1¼ inch	140–145°F (medium)	24–29 minutes
1½ inch	120–125°F (rare)	18–23 minutes
1½ inch	130–135°F (medium-rare)	23–28 minutes
1½ inch	140–145°F (medium)	27–33 minutes

How To Use A Thermometer So The Timer Stops Bossing You Around

A lean steak gives you a narrow window. That’s why the thermometer matters more than the clock. If you’ve only used one for turkey, you’ll be surprised how easy it is with steak.

Where To Probe

Insert the probe into the thickest part from the side, not straight down from the top. Aim for the center. If the steak has a fat cap, avoid pushing the tip into fat, since fat reads hotter than lean meat.

When To Start Checking

Start checking 4–6 minutes before the low end of your time range. If the steak is thin, check even earlier. A single extra minute can push a lean cut past the texture you want.

Carryover Heat Is Real

After you pull the steak, its temperature keeps rising as heat moves inward. For London broil, a rise of 5–10°F during the rest is common, depending on thickness and how hot the surface got during searing.

Seasoning That Works With A Lean Cut

London broil doesn’t need a long ingredient list. It needs salt early enough to do its job, plus a little fat to help browning.

Quick Dry Brine

Salt the steak 45–90 minutes before cooking, then leave it on a plate in the fridge, open to the air. The surface dries slightly, which helps crust, and the salt seasons deeper than a last-second sprinkle.

Simple Spice Blend

• 1 to 1½ teaspoons kosher salt per pound
• 1 teaspoon black pepper
• 1 teaspoon garlic powder
• ½ teaspoon smoked paprika
• 1 teaspoon neutral oil for the surface

If you like a brighter finish, add a squeeze of lemon after slicing, not before baking. Acid before heat can tighten the surface of lean beef.

Resting And Slicing: The Part That Makes Or Breaks London Broil

Most “tough London broil” stories come down to two things: skipping the rest, and slicing with the grain. Fix those and the same cut eats like a different dinner.

How Long To Rest

Rest 8–12 minutes on a cutting board. Tent loosely with foil if your kitchen is cold. Don’t wrap tight. Tight foil traps steam and softens the crust you worked for.

How To Find The Grain

Look for the long muscle lines running across the steak. Rotate the steak so those lines run left to right. Then slice straight down so each slice crosses the lines. That shortens the muscle fibers, which makes chewing easier.

How Thin To Slice

Aim for slices about ¼ inch thick. If the steak still feels firm, go thinner. Thin slices hide a lot of sins on a lean cut.

Table: Common Results And Fixes For Next Time

This table is your fast diagnostic. Pair it with the thermometer notes above and you’ll get repeatable results.

What You See	Likely Cause	Fix Next Time
Dry, crumbly slices	Pulled too late	Pull 5–10°F earlier and rest longer
Gray band with tiny pink center	Heat too high too long	Sear shorter, check earlier, rest fully
Chewy even when medium-rare	Sliced with the grain	Turn the steak and slice across the lines
Soft, pale surface	Surface wet	Pat dry, salt earlier, use a rack
Burnt spices	Sugar-heavy seasoning	Skip brown sugar; finish with a glaze after
Center undercooked, edges done	Steak uneven thickness	Trim or fold thin end under; tie with twine
Salty outside	Salted right before cooking	Salt earlier so it dissolves and spreads
Juices flooding the board	No rest	Rest 8–12 minutes before slicing

Broil Finish Option For A Deeper Crust

If you want a darker surface without overcooking the center, use a short broil at the end. It works well when you bake on a rack.

How To Do It

1. Bake at 400°F until the steak is 10–15°F below your pull temperature.
2. Switch the oven to broil. Move the rack so the steak sits 4–6 inches from the broiler element.
3. Broil 60–90 seconds, then flip and broil 60–90 seconds more.
4. Check temperature, then rest.

Broilers vary a lot. Stay close and watch the surface. A minute can swing from browned to bitter.

Serving Ideas That Keep The Meat Tender On The Plate

London broil tastes best when it’s sliced and served with something that adds moisture. That can be a pan sauce, a cold topping, or a side that carries juices.

Fast Pan Drippings Sauce

If you seared in a skillet, set the steak on a board to rest. Put the skillet over medium heat and add ½ cup beef broth. Scrape the browned bits, simmer 2–3 minutes, then whisk in 1 tablespoon butter off heat. Spoon over slices.

Cold Toppings

• Chopped parsley and lemon zest
• Thin-sliced onions soaked in ice water, then drained
• Horseradish stirred into plain yogurt

Leftover Plan

Chill leftover slices quickly, then use them cold in a sandwich or salad. Reheating lean steak dries it out. If you must warm it, do it gently in a covered pan with a splash of broth.

Food Safety Notes Without The Panic

Raw beef can carry germs, so clean handling matters. Use separate boards for raw meat and ready-to-eat food, wash hands after touching raw beef, and chill leftovers within two hours.

A thermometer is also a safety tool. If you’re new to instant-read thermometers, the USDA’s tips on correct placement and use can save you from bad readings and overcooking. USDA FSIS food thermometer basics lays out the core steps.

One-Page Checklist For Repeatable Results

• Measure thickness at the thickest point.
• Salt 45–90 minutes early, then keep the surface dry.
• Heat the oven to 400°F. Use a rack or a preheated skillet.
• Start checking temperature 4–6 minutes early.
• Pull at your target temperature, then rest 8–12 minutes.
• Slice thin across the grain.
• Serve with a sauce or a juicy side.

If you remember just two moves, make them these: pull early and slice across the grain. That combo keeps a lean steak tender and worth repeating.