What does the Alliance Tower Defense calculator do?
It converts your observed match results into planning numbers: enter Coins per completed match, minutes per match, and your success rate, and it projects whole matches and Coins for a session. It is arithmetic on your inputs — no payout rate is prefilled, because the developer publishes none.
What Coins per match should I enter?
The documented mode rewards are 100 (Easy), 275 (Medium), 500 (Hard), 850 (Insane), and 1,000 (Crazy). If your result screen shows something different, trust your screen and update the wiki-quoted value — rebalances happen.
How accurate is the estimate?
Exactly as accurate as your inputs. Five measured clears give a solid Coins-per-clear and minutes-per-match; the success rate is where optimism creeps in, so use your recent record, not your best run.
What can I do with a 850 Coins estimate?
A 10-pull is the natural unit of spending: divide your projected Coins by 850 to see pulls per session, then read the summon guide for the odds you are buying into.