Depends on how fast you go. This week I did a 5 and a half minute speech 1200 words. So I'd say 3 to 3.5 pages in font 12 Times New Roman. You could do 4 pages possibly; though you don't want to talk too fast.
The average speaking rate rests at around 120-180 words per minute. Therefore, for your speech, you shouldn't write any more than 1800. Personally, I'd be aiming for the 1200 mark, possibly even less to allow for emphasis.