You need to consult a generalized headwind tailwind landing distances plot. FAA-H-8083-25 "PHAK" has one.
In this case we have a 25-knot headwind which equals 25% of the speed for the no-wind takeoff. Using the plot, we get a 42% reduction in takeoff distance, or 462 ft discount. Takeoff distance in this headwind will be 638 ft. Your mileage may vary, always use the POH in real life. This is just to get an idea what the trade off is.
[edit] That sounded kind of generous to me so I looked up some headwind discounts in a few of my POHs I found it to be a bit optimistic in comparison to real values. Probably more like 10-15% discount on takeoff distance per 10 knots of headwind.
Last edited by Cubdriver; 02-06-2011 at 06:31 AM.