going from stock re070's to toyo t1r tires with the size 245/40/18. was curious if this would raise my car up ALOT. is there a way to measure it?

i was planning on raising my car for more ground clearance, because my v-limited didn't like how low my car was with the 17's.. now that im going 18's, im wondering if i should bother raising my suspension after i throw on the 18's.

http://www.miata.net/garage/tirecalc.html

thanks.

it says i went from a radius of 12.5 to 12.9 inch.

does that mean my car was raised by .4"?

It says the diameter will increase .7 and the radius .4 so I'd guess between .35"-.4".