You will want to be as exact as possible when measuring. Open your grill and measure the inside area that your grates sit on. The width is from left to right. This normally will be the wider number. Depending on the size of your grill, you will need to deduct either 2 or 3 inches from the total width. (2 inches if griddle total width is less than 30 inches or 3 inches for anything over 30 inches wide) This will give heat a way to escape from your grills underneath side. Remember your grill is made for the heat just to rise. We are asking you to allow at least (2 inches, 1 inches on each side for the heat to be able to escape.
Now the depth, measure from front to back. This is the measurement you will want to be the most careful on. Make sure you leave 1/8 to 1/4 inch of room, so the Griddle will just fit in place. If your depth is exactly 19 1/8, order a top that is 19. Do not order a top that will fit exactly in your grill. This is steel. It can expand. we want room for it to fit easily. You usually have a lip that your grates set on that is 1/2 inch on the front and 1/2 inch on the back. Make sure you give yourself a little play room for your top to fit.
The height / Lip is just how high of a lip you want on the griddle top. We bend each side up. Usually 1 to 3 inch. The 3 inch lip has become the most popular. It acts as a back splash and allows you to sear the side of the steak at the same time. If you order 2” or higher, we will automatically taper the left and right side near the front of the griddle to a 1 ½ inch front. Making for a easy use of your griddle top. Make sure your grill has room on all 4 sides for whatever size lip you request.