I have to write a paper with the requirement to use "1.5 line spacing" 12pt Times New Roman. Naturally I used
\usepackage{setspace}
\begin{document}
\onehalfspacing
Lorem ipsum…
So far so good. But I'm a litte paranoid so I checked it with Word and was suprised to get something completely different, so I made this comparison:

you may have to open that in a new tab.
But seriously? Am I missing something? Everyone recommends using \onehalfspacing but that can't be right? I checked the text with a bare minimum and the results are the same:
\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{mathptmx}
\usepackage{setspace}
\begin{document}
\onehalfspacing
Lorem ipsum...
I guess my question is: what setting should I use?

setspacesolution will be just fine. – jon Aug 4 '12 at 23:48