Board Thread:Boruto Discussions/@comment-31278419-20170415051621/@comment-734582-20170417155044

Dimension Creator wrote: Naruto used hundreds of clones to train his wind release and wind release rasengan that only five clones thing applies only to training and using sage mode. The only time in the series he does anything like that, and even then he reduced the number of clones as the training progressed (it starts with "one for every leaf" to a couple of dozen on the waterfall). Every other time he sent out mass clones, it was for either distraction or reconnaissance (or in other words: extremely basic tasks).

EDIT: even in the manga it's an indeterminate amount. Looks to be around a hundred or so for the leaf phase. It also caused him to nearly pass out. If he's using shadowclones all day, he simply cant use hundreds.