For most ovens, the answer to “how long to cook london broil in oven at 400?” is 15–25 minutes, depending on thickness, doneness, and a 10-minute rest.
If you love a hearty beef dinner but do not want to hover over the stove, baking London broil in the oven at 400°F is a smart weeknight move. The challenge is simple: cook it long enough to reach a safe, juicy center without turning that lean cut into shoe leather. A clear time range, a meat thermometer, and a short rest are all you need.
This guide breaks down how long to cook London broil at 400°F based on thickness, weight, and your preferred doneness. You will see oven time charts, a step-by-step method, and an internal temperature guide so you can pull the pan with confidence instead of guessing.
How Long To Cook London Broil In Oven At 400? Basics You Need
London broil is usually a top round steak or roast, around 1 to 2 inches thick. In a 400°F oven, most pieces take somewhere between 15 and 25 minutes after an initial sear, with the exact timing driven by thickness and target internal temperature.
For a marinated London broil that is about 1½ inches thick, a common pattern is:
- Sear in a hot skillet for 2–3 minutes per side.
- Finish in a 400°F oven for about 12–18 minutes.
- Rest for 10 minutes before slicing against the grain.
The oven portion is where the question “how long to cook london broil in oven at 400?” comes in. Use the ranges below as a starting point, then let the thermometer be the final judge.
London Broil Time Range At 400°F
| Thickness | Doneness Target | Approx Time At 400°F* |
|---|---|---|
| 1 inch (about 1 to 1.25 lb) | Medium-rare (130–135°F) | 10–14 minutes |
| 1 inch (about 1 to 1.25 lb) | Medium (140–145°F) | 14–18 minutes |
| 1½ inches (about 1.5 to 2 lb) | Medium-rare (130–135°F) | 15–20 minutes |
| 1½ inches (about 1.5 to 2 lb) | Medium (140–145°F) | 20–25 minutes |
| 2 inches (about 2 to 2.5 lb) | Medium-rare (130–135°F) | 20–26 minutes |
| 2 inches (about 2 to 2.5 lb) | Medium (140–145°F) | 26–32 minutes |
| Any thickness | Well done (160°F+) | Add 4–6 minutes to medium range |
*Times assume the meat starts near room temperature after marinating, is seared first, and cooks in a preheated 400°F oven in a heavy pan. If you skip the sear, expect a slightly longer oven time.
London Broil Oven Time At 400 Degrees With Different Factors
The table gives a solid starting point, but real-life cooking is rarely that neat. A few details can stretch or shrink the range quite a bit. If your London broil always seems overdone or underdone, one of these factors is usually the culprit.
Meat Thickness And Weight
Thickness matters more than total weight. A long, flat piece that weighs 2 pounds but stays under 1 inch thick cooks much faster than a compact 1½-inch slab at the same weight. When you look at store labels, do not lock in on pounds alone. Give the steak a quick look from the side and group it in your mind as thin (about 1 inch), medium (about 1½ inches), or thick (2 inches or more).
Once you know that rough thickness, the time ranges for 400°F become much easier to apply. If you fall between sizes, choose the shorter end of the higher range and rely on the thermometer as you approach the end.
Starting Temperature Of The Meat
Cold meat straight from the fridge can add several minutes to your oven time at 400°F. If you can, pull the London broil from the refrigerator 30 to 45 minutes before cooking. Pat it dry, season it, and let it sit on the counter while the oven preheats. The center will still be cool, but the chill comes off the surface, which helps with browning and more predictable timing.
Oven Accuracy And Pan Type
Home ovens rarely hold a perfect 400°F. Some run hot; others lag behind. A cheap oven thermometer hung on the rack gives you a clear picture and helps explain why a recipe that claims “18 minutes” sometimes needs 22 in your kitchen.
The pan you choose also matters. A thick cast-iron skillet holds heat and can keep the underside of the steak cooking even as you slide the pan into the oven. A thin, lightweight sheet pan cools faster and often needs a few extra minutes to reach the same internal temperature.
Marinade, Oil, And Sugar Content
London broil recipes often lean on marinades with soy sauce, vinegar, and a bit of sugar. Sugar encourages browning, which can trick you into thinking the steak is done sooner than it really is. If your marinade contains honey, brown sugar, or sweet sauces, pay extra attention to the thermometer rather than the color of the crust.
A thin coat of oil on the surface also helps the meat brown in the oven at 400°F. That deep color is tasty, but it can appear before the center reaches a safe temperature, especially on thicker cuts.
Safe Internal Temperature For London Broil
Time charts are helpful, but the safest way to judge London broil is by internal temperature. Food safety agencies recommend that whole cuts of beef, such as steaks and roasts, reach at least 145°F with a short rest. The Safe Minimum Internal Temperature Chart for Cooking lists 145°F plus a 3-minute rest for beef steaks and roasts.
The same advice appears in USDA beef steak temperature guidance, which treats 145°F and a short rest as the baseline for safety. Many home cooks still prefer to pull London broil a bit lower, around 130–135°F for medium-rare, then let carryover heat bring it closer to that guideline as it rests.
Doneness Levels For London Broil
Here is a quick internal temperature guide you can match to the time ranges in the next table. These numbers describe the temperature in the thickest part of the steak after a brief rest:
- Rare: 120–125°F, cool red center.
- Medium-rare: 130–135°F, warm red center.
- Medium: 140–145°F, pink center.
- Medium-well: 150–155°F, slight blush.
- Well done: 160°F+, little or no pink.
If you want to stay as close as possible to official safety guidance while still keeping the meat tender, aim for medium, around 140–145°F in the oven, then let the London broil rest so the juices settle and the internal temperature levels out.
Step-By-Step Method For London Broil At 400°F
Now that you have a feel for the timing and temperatures, here is a simple method that fits most 1 to 2-inch London broil cuts. You can adjust spices and marinade flavors to your taste, but keep the steps in this order for predictable results.
1. Marinate And Season
London broil is lean, so a marinade helps soften the texture and add flavor. A classic mix includes oil, an acidic ingredient, salt, and aromatics. Think olive oil, soy sauce, red wine or balsamic vinegar, garlic, and herbs. Place the meat in a shallow dish or zipper bag, pour the marinade over, and chill for at least 2 hours. An overnight soak deepens the flavor, as long as the acidic part stays moderate so the surface does not turn mushy.
Before cooking, take the meat out of the marinade, pat it dry, and season lightly with extra salt and pepper. A dry surface browns faster and more evenly in a hot pan.
2. Bring To Room Temperature And Preheat
Set the marinated London broil on the counter for about 30 minutes. During that time, place a heavy skillet or roasting pan in the oven and preheat to 400°F. Preheating the pan means the meat starts cooking the moment it touches the metal, which shortens oven time and gives the underside a nice sear.
Have your meat thermometer ready. An instant-read style is ideal, since you can check the center quickly without leaving the oven door open for too long.
3. Sear, Then Finish In The Oven
There are two easy routes here. You can sear on the stove and move the pan to the oven, or you can preheat the pan in the oven and sear once the meat goes in. Either way, the idea stays the same: a brief blast of high heat on the surface, then steady cooking at 400°F until the center reaches your target temperature.
- Heat a cast-iron skillet on the stove over high heat with a thin film of oil.
- Sear the London broil for 2–3 minutes per side until a deep brown crust forms.
- Move the skillet to the preheated 400°F oven.
- Roast, checking the internal temperature after 10 minutes for thinner pieces and after 15 minutes for thicker ones.
- Pull the pan when the thermometer reads about 5°F below your goal, since the temperature rises a bit during the rest.
For many home cooks, that means pulling around 130°F for a medium-rare finish or around 140°F for a medium center after rest.
4. Rest And Slice Against The Grain
Once the pan comes out of the oven, tent the London broil loosely with foil and rest for at least 10 minutes. This pause gives the juices time to redistribute so you do not lose them all on the cutting board.
When you slice, turn the meat so you can clearly see the grain running through it. Use a sharp knife and cut thin slices at a slight angle across the grain. This shortens the muscle fibers and makes each bite feel more tender, even if you prefer a medium or medium-well center.
400°F Oven Time And Temperature Cheat Sheet
Once you have cooked London broil a few times, you might not need a full recipe. A small chart on your fridge or phone is often enough. The table below pairs oven time ranges at 400°F with internal temperatures for a typical 1½-inch London broil that started near room temperature and was seared first.
| Doneness Level | Target Internal Temp* | Approx 400°F Time Range |
|---|---|---|
| Rare | 120–125°F | 10–14 minutes |
| Medium-rare | 130–135°F | 15–20 minutes |
| Medium | 140–145°F | 20–25 minutes |
| Medium-well | 150–155°F | 24–28 minutes |
| Well done | 160°F+ | 26–32 minutes |
| Thin steak (about 1 inch) | 130–145°F | 10–18 minutes |
| Thick roast (about 2 inches) | 130–145°F | 20–32 minutes |
*Temperatures listed are targets in the thickest part after a brief rest. Pull the meat from the oven a couple of degrees before the final number to account for carryover heat.
Common Mistakes When Cooking London Broil At 400°F
Even with clear timing and temperature numbers, a few habits can still spoil London broil in a 400°F oven. If you have ever ended up with tough slices or a gray, dry center, one of these patterns probably played a role.
Skipping The Thermometer
Relying on the clock alone is risky, especially with a cut that can swing from juicy to dry in only a few minutes. A quick thermometer check near the center gives you real data. Slide the tip in from the side so it sits in the thickest part, away from the pan and any large pockets of fat.
Once you trust your thermometer, the question “How Long To Cook London Broil In Oven At 400?” turns into a simple pattern: cook within the time range, check the temp, rest, and slice.
Cooking Straight From The Fridge
Putting an ice-cold London broil straight into a 400°F oven stretches the time and encourages uneven cooking. The outside can dry out before the center reaches a safe temperature. Letting the meat stand at room temperature for a short window smooths out that curve and gives you more reliable results.
Cutting Too Soon Or With The Grain
Cutting right after the pan comes out releases a flood of juices and leaves the slices dry. On top of that, cutting in the same direction as the muscle fibers forces you to chew through long strands. A short rest and thin slices across the grain fix both issues at once.
Quick Reference For London Broil In Oven At 400°F
When you need a fast answer on a busy night, keep three points in your head. First, aim for a preheated 400°F oven and a good sear, then plan on 15–25 minutes for most 1 to 2-inch London broil cuts. Second, match the time to thickness, not just weight. Third, use a thermometer and rest the meat before carving.
With those habits in place, How Long To Cook London Broil In Oven At 400? stops feeling like a guess. You can adjust for your oven, your pan, and your favorite level of doneness, and plate tender slices that work just as well for a weeknight dinner as they do for guests.