Weight supported by garage door springs???

My single car garage door weighs 180 lbs -

when looking for extension springs to replace my worn out ones.  The box comes with a pair of springs rated with a weight in lbs.  Would I get the 90 lb rating since I assume each spring supports 90 lbs???

If your door weighs 180lbs then you would use a pair of 180lb springs. If you have 90lb springs you would need 4 of them (2 on each side) to pull the correct weight. There's a color code used for getting the correct springs - 180lb springs will have Gold color painted on the ends. The most common length of the springs for a 7' high door = 25" while a 27" spring would be for an 8' high door.