It's basic pay plus SSR or locality, whichever is higher. Basic pay is base pay before locality or CIP if you get it. It'll be on your SF50.
So take the basic pay, add the 30% SRR or locality, whichever is higher, then go to the GS pay table and find your grade, should be 11 or 12. Then look at what step in that grade it puts you at. If that's higher than the max then you'll just be stepped out at step 10. Then ad 5% ATC premium pay for AF, not sure if all Navy bases get that.
example:
basic pay $67,500+34.89% locality = $91,050, which comes out to GS11 step 5 at $90,683
plus 5% ATC premium comes to $95,217