Website gives you a option to recalculate but doesn't take your calculations you have to try over and over again to get it to take it, and the outcome is you receive measurements that you never ordered. I called a couple of times for help with the website and the person just told me what to do and didn't seem very concerned that I was having problems with their website once I got the package and figured out that it wasn't the right size I called back and they told me that they didn't Take returns on the 12 by 12 that's not what I ordered! They don't value their customers this is a terrible company.