How Long to Cook London Broil
London broil refers to a cooking method, typically using top round or flank steak that is marinated and broiled or grilled.
The Short Answer
London broil refers to a cooking method, typically using top round or flank steak that is marinated and broiled or grilled. Cook to an internal temperature of 145 degrees F.
Use an instant-read thermometer inserted into the thickest part.
Cooking Methods
🔥 Oven
Temperature: 450°F
Time: 12–18 minutes
Broil 6 inches from the element. 6-9 minutes per side for a 1.5-inch thick steak. Use the broiler, not regular baking. Marinate for at least 4 hours first.
Rest: 10 minutes
🔥 Grill
Temperature: 500°F
Time: 10–14 minutes
High direct heat, 5-7 minutes per side for medium-rare. Marinate for several hours before grilling. Slice thin against the grain.
Rest: 10 minutes
🍳 Stovetop
Time: 5–7 minutes
Per side in a cast iron skillet over high heat. Sear hard and fast. Best for steaks under 1.5 inches thick. Finish in a 400 degree F oven for thicker cuts.
Rest: 10 minutes
London broil is a lean, tough cut that relies entirely on two things: a good marinade (at least 4 hours, ideally overnight) and proper slicing (thin, against the grain). Skip either step and you will have shoe leather. Nail both and you have a steakhouse dinner for a fraction of the price.
Frequently Asked Questions
London broil is a cooking method, not a specific cut. It typically uses top round or flank steak. Some butchers label top round as London broil. The key is that it is a lean cut that benefits from marinating.
Minimum 4 hours, ideally overnight (8-12 hours). The acid in the marinade tenderizes this lean, tough cut. Do not marinate more than 24 hours or the texture becomes mushy.
Three likely causes: not marinating long enough, overcooking past medium, or slicing too thick or with the grain. Slice thin, against the grain, for the most tender result.
The Bottom Line
London Broil cooking times vary by method and thickness. Always verify doneness with a thermometer reading 145 degrees F. The times above are guidelines; your specific results depend on the size and starting temperature of your food.