The regular fit band that I bought list the circumference from 5.4 inches to 7.4 inches and will go to 8 inches in the last notch, there is also available a X-Large fit band but it list it's size to be 7.1 inches to 8.8 inches, I'm not sure what it will go out to but it may be a close fit at best, there may be larger bands on their web site but I'm not sure.