John_T speaks the truth, as usual, the 50%/150% factors are built in to the Takeoff performance data given you, there's no need for you to apply any correction to the actual wind. A point or two to remember however......
(1) The 50%/150% factors give you a bit of "fat" for the Takeoff calculation. In calm wind conditions, you have no built-in "fat" at all. (50% or 150% of Zero is still zero).
(2) Pre-flight number crunching is typically done 20 to 30 minutes prior to Takeoff using the ATIS wind or your own observation if ATIS is unavailable. If, at the time of actual Takeoff, the headwind has decreased, or the tailwind increased, then, if the change is less than the built in margin (e.g. 8 Kt Headwind instead of 10 Kt), then aim it and go, you are merely using a little of the built-in margin. (ATC typically provide a wind check included with the Takeoff clearance). If the wind component has changed by MORE than the built-in margin, it's time to do a recalculation before departure. (The latter is most appropriate if you were at performance limiting weight or you are using Reduced Thrust (Assumed Temp / Flex). It amazes me how many people do not do this last moment check
Regards,
Old Smokey