I couldn't find a time estimate on Wikipedia, but Pearson (the publisher of the WAIS-IV) says that it takes 60-90 minutes (http://www.pearsonassessments.com/HAI

I couldn't find a time estimate on Wikipedia, but Pearson (the publisher of the WAIS-IV) says that it takes 60-90 minutes (http://www.pearsonassessments.com/HAIWEB/Cultures/en-us/Productdetail.htm?Pid=015-8980-808 http://www.pearsonassessments.com/HAIWEB/Cultures/en-us/Prod...). It's also not clear to me how they determined correlations between scores on their on-line version and on the standard pencil-and-paper version.