How Long To Grill London Broil Medium | Steakhouse Timing

For a 1-inch cut, grill about 5 to 7 minutes per side over high heat, then rest it until the center settles at medium.

London broil can be a little tricky on the grill. It’s lean, it can tighten up fast, and one extra minute can push it from juicy to dry. The good news is that medium is a sweet spot for this cut. You get a warm pink center, better chew, and enough heat to melt the fat and wake up the marinade.

If you want a straight answer, start with 5 to 7 minutes per side for a steak about 1 inch thick over direct high heat. Then rest it for 5 to 10 minutes and slice it thin across the grain. That timing works as a starting point, not a guarantee. Thickness, grill heat, and the cut itself can shift the clock.

The best way to nail it is to treat time as a range and temperature as the finish line. Pull the meat when the thickest part hits about 140°F to 145°F for medium, with the higher end lining up with the U.S. food safety target for whole cuts after a short rest.

Why London Broil Timing Is Never Just One Number

“London broil” often refers to a cooking style and a lean beef cut such as top round or flank. Those cuts do not cook the same way as a ribeye or strip steak. They have longer muscle fibers and less marbling, so they reward control more than brute heat.

That’s why two people can cook “the same” London broil and get different results. One steak may be 3/4 inch thick, another may be 1 1/2 inches. One grill may run hot in the back corner, another may lose heat every time the lid opens. A sugary marinade can darken the outside long before the center is ready.

For medium doneness, your job is simple: build color on the outside, stop before the center climbs too far, then let the rest finish the job. Once you learn that rhythm, this cut gets a lot easier.

How Long To Grill London Broil Medium On A Gas Grill

On a properly heated gas grill, a 1-inch London broil usually needs about 10 to 14 minutes total for medium. Grill it over direct high heat with the lid closed between flips, then rest it off the heat. Thicker cuts may need a quick move to a cooler zone after searing.

Start With The Right Setup

• Preheat the grill for 10 to 15 minutes.
• Clean and oil the grates so the meat releases cleanly.
• Pat the surface dry before grilling, even if you marinated it.
• Season after drying if your marinade is light on salt.
• Use a thermometer. Guesswork is where London broil goes sideways.

A wet surface steams before it sears. That slows browning and can leave the outside gray. Drying the meat first gives you better crust and a cleaner read on how fast it’s cooking.

Use Time As A Range, Not A Rule

If your steak is under 1 inch thick, stay close. It can hit medium in a hurry. If it’s over 1 1/4 inches, sear first, then shift it to a cooler part of the grill to finish without burning the outside.

Pulling by temperature beats chasing a clock. The safe minimum internal temperature chart lists 145°F with a rest for whole cuts of beef. If you prefer a pinker medium, pull a touch earlier and let carryover heat finish it.

Thickness	Total Grill Time For Medium	Pull Temperature
3/4 inch	8 to 10 minutes	138°F to 140°F
1 inch	10 to 14 minutes	140°F to 143°F
1 1/4 inches	12 to 16 minutes	140°F to 143°F
1 1/2 inches	14 to 18 minutes	140°F to 145°F
Direct high heat only	Best for thinner cuts	Watch closely after first flip
Sear then indirect finish	Best for thicker cuts	More even center color
Rest time	5 to 10 minutes	Center rises a few degrees

What Changes The Grill Time Most

Thickness comes first. A flat, thin London broil may reach medium before the surface gets deep color. A thicker one may need extra time after the sear. Start checking early and don’t wait for the meat to “feel done.” Lean beef tightens fast once it crosses the line.

Marinade changes the cook too. Acid and salt can help tenderness and flavor, yet sugar speeds browning. If your marinade contains honey, brown sugar, or sweet sauces, wipe off the excess before the steak hits the grates.

Food safety matters during prep. The FSIS grilling and food safety guidance says meat should marinate in the refrigerator, not on the counter, and any used marinade needs to be boiled before it goes back on cooked meat.

Why Resting Matters So Much Here

London broil gets a bad name when it’s sliced right off the grill. The juices rush out, the fibers stay tight, and each bite feels drier than it should. A short rest gives the juices time to settle and lets the center finish cooking gently.

If you pull the steak at 140°F to 143°F, it often lands in the medium zone after resting. That small gap is where you save the meat from overshooting.

Step-By-Step Timing For A Tender Medium Finish

1. Preheat one side of the grill to high and leave a cooler side available.
2. Take the meat from the fridge 20 to 30 minutes before grilling so the center is not ice cold.
3. Pat dry and season the surface.
4. Grill over direct heat for 5 to 7 minutes on the first side.
5. Flip and grill 4 to 7 minutes on the second side.
6. Check the thickest part with a thermometer.
7. Move to the cooler side if the outside is done and the center still needs time.
8. Pull at 140°F to 145°F, then rest 5 to 10 minutes.
9. Slice thin across the grain.

If you store the meat ahead of time, follow the FDA note to marinate food in the refrigerator and keep raw beef chilled until grill time. Small prep habits make a big difference once heat enters the picture.

If This Happens	What It Usually Means	What To Do Next
Outside is dark, center is still cool	Heat is too fierce for the thickness	Shift to cooler zone and close the lid
Steak sticks to grates	Surface is wet or crust is not set	Give it 30 to 60 more seconds
Center jumps past medium fast	Steak is thin or grill is running hot	Check earlier on the second side
Meat tastes dry	It cooked too far or rested too little	Pull earlier next time and rest longer
Chew feels stringy	Slices ran with the grain	Turn the steak and slice across the lines
No crust forms	Grill was not hot enough	Preheat longer before the steak goes on

How To Slice London Broil So Medium Stays Tender

You can cook this cut well and still end up with a tough plate if you slice it the wrong way. London broil has long muscle fibers. When you cut across them, each bite gets shorter strands and feels softer.

Set the steak on a board and find the lines running through the meat. Turn your knife so it cuts across those lines, not along them. Thin slices work better than thick slabs here. That one move can do as much for tenderness as the marinade.

Best Serving Moves After Grilling

• Slice thin and fan it across the board.
• Spoon any resting juices over the meat.
• Pair it with chimichurri, grilled onions, or roasted potatoes.
• Use leftovers cold in sandwiches or warm in steak salads.

Medium London broil should not be dripping red, and it should not be gray edge to edge. You want a warm pink center, browned edges, and slices that bend a little before they break.

Common Mistakes That Ruin The Timing

The first mistake is trusting time alone. Grill models run differently, weather shifts the heat, and no two steaks are identical. Time gets you close. Temperature gets you home.

The second mistake is skipping the rest. Cutting too soon drains the board and leaves the meat tighter. The third is slicing with the grain. That can make a properly cooked steak feel like it missed the mark.

One more trouble spot is over-marinating in harsh acid. A few hours can help. Too long can make the outside mushy while the inside still feels firm. If your marinade is heavy on vinegar or citrus, shorter is safer.

My Best Rule Of Thumb For Medium London Broil

For most backyard grills, think 5 to 7 minutes per side for a 1-inch cut, pull at 140°F to 145°F, rest 5 to 10 minutes, then slice thin across the grain. That pattern works far better than chasing a single magic number.

Once you do it once or twice, the guesswork fades. You start reading the meat, not the stopwatch, and London broil stops feeling like a gamble. That’s when this budget-friendly cut starts earning a regular place on the grill.