18 inches long x 12 wide x 4“ tall + 4” tall. You should measure, but it might fit your lasagna pan. This is a double casserole carrier. You put a cold casserole in the bottom silver layer and a hot casserole in the top layer. Of course both your casseroles need to have lids and if you’re going to stack them like this, you need a firm lid on the bottom casserole or it needs to be a smaller rectangle than the upper dish. Both sections are insulated and the upper section is safe to put a hot dish in right out of a 350 degree oven. Of course you don’t have to use both sections at the same time you can choose to carry just one dish at a time. This bag has one of those all around zippers, like expandable luggage, so that you can collapse the top section into itself when you’re not using it. And then this has long straps that you can Velcro the padded carry handle around to make it easy to carry. Your casserole holder is sealed in a bag. I bought 2 but I’ve only used 1, which I’m keeping, & I’m selling the other one. The photos I showed of an open tote are my own that I’m keeping. Monogrammed with the letter H but you can pretend that stands for “hot” or “howdy” if your name doesn’t start with an H. Nonsmoking home.