CPM, CPC and CPA calculator

The solver walks five relations to a fixpoint: cost equals impressions times CPM over a thousand, cost equals clicks times CPC, cost equals conversions times CPA, clicks equal impressions times CTR, and conversions equal clicks times CVR. CTR is a percentage of impressions and CVR of clicks. If two of your entries derive the same number two different ways, the tool refuses instead of averaging; fix the contradicting input. The budget line inherits any rounding from derived rates. This is arithmetic only: no reach estimation, no frequency model, no currency conversion.