There is typically 18" (84" - 30" - 36") between the counter and the bottom of the standard 30" wall cabinet.
Normal top of cabinets is 84" minus a 12" wall cabinet would be 72" to the cabinet bottom/microwave top - minus 16"+/- for the microwave = 56" leaving approx. 20" to reach the top of the 36" tall range. The microwave would be approx. 2" above the standard 30" wall cabinet.
An 18" wall cabinet would get you to 66" to the cabinet bottom/microwave top - minus 16"+/- for the microwave = 50" leaving 14" to reach the top of the 36" tall range. The microwave would be about 4" below the standard 30" wall cabinet.
A 15" wall cabinet would put you in the middle of the two above.
Anything between 14" to 20" is typical.