I'm not 100% sure. I know a large will but I'm not sure about 1x. In a couple hours I can measure it while stretching it and I'll let you know in a comment how much it measures
I measured it and it won't fit for a 1x, sorry, they stretch up to 20 inches, that's a 40inch diameter which is just a little bigger than large but not as big as a 1x. Sorry :/