Board Thread:Questions and Answers/@comment-24053029-20131015040837/@comment-3445779-20131015182230

223.27.94.3 wrote: Well..I heard that hata will continue till december...till maria birthdate (according to the progress of manga time)...so it will take 2-4 years to complete...We are expecting 150+ chapter ..Since each volume contains about 10-11..so I think 15-16 more volumes will be released....current volume is 38 .................So total number stands about 54-56

It's a possibility that the total number of volumes for the manga series would be around that number, but you gotta remember anything can happen. Such as if the series went on hiatus or if Kenjiro Hata stretched the series out and made it longer. So for now its unknown how many volumes there will be for Hayate no Gotoku!