How much lift do you get from coil spacers?

[longarch]

I have a Tracker with 30x9.50x15 tires on it and it has minor rub on the inside edge of the inner fender.The gap above my rear tires is 4" and the gap above my front tires is 2-5/8". Does anyone know exactly how much lift a 1-1/2" and/or a 2" coil spacer will lift the front end? I've heard a 1-1/2" will lift about 2" and a 2" will lift about 3" but I want to hear from someone who has experience with this.