How much wallpaper do I need? That’s a great question! And it isn’t hard to figure out.
One solid search on the internet for “wallpaper calculator” will turn up a bunch of results for automated engines that will crunch the numbers for you. How handy! But I’ll admit that I don’t trust someone else’s code when I’m trying to figure out how much wallpaper I need for a project. PARTICULARLY when that wallpaper has a repeat pattern, which is most of the time. I really prefer pencil, paper and a calculator.