I've seen cloth masks for sale in only two stores so far. One was Target, which had only two sizes. Neither fit (I tried them both). The pharmacy in the supermarket where my dad shops also has masks, but the same issue obtains; you won't know if they'll fit unless you buy them.
Of course there are thousands upon thousands listed on the Internet, and even on websites for individual stores, such as Walmart, but it always seems to be the same deal, you won't know if they'll fit unless you buy them and try them.
My dad and I both have been using disposable masks. They at least have elastic bands, so that they fit or can be made to fit. After developments this week, I've started wearing two of them at a time.
Until now, I've had only one cloth mask that fit, and that was luck. It was included as a surprise in the package for something I bought on eBay.