The docs for splitTextToSize (http://raw.githack.com/MrRio/jsPDF/master/docs/module-split_text_to_size.html#~splitTextToSize) specify, that one has to calculate 72 / 25.6 to use millimeters instead of inches.

I think it should be 72 / 25.4, since 1 inch is 25.4 millimeters, and not 25.6.