Your average collected job revenue in USD, your gross margin as a percentage, the fixed reward you are considering in USD, and optionally how many closed referred jobs a month you expect, which defaults to one. Figures are bounded and validated, no formatted marketing text is parsed, and there is no currency conversion: Revvin prices in USD everywhere.
The gross profit on one closed referred job before the reward, which is revenue multiplied by margin. The gross profit after the reward. The total rewards you would pay at the monthly volume you chose. The contribution left after those rewards, which is not net profit because your overheads are not included. If the reward is the same as or larger than the gross profit, it says so plainly so you can revisit the economics.
When the post-reward contribution is positive, the calculator shows how many closed referred jobs would cover Revvin Pro at $49/month USD, and how many would cover $450/year billed once for a year. When the reward leaves nothing, it says no number of jobs would cover it rather than showing a figure. Publishing your referral page is free either way, so Pro is the only subscription in the comparison.
It does not recommend a reward, a percentage or a payout rule, it does not promise profit or results, it never treats revenue as profit, and it is not accounting advice. It is your own arithmetic, done for you, on figures only you can supply. Nothing you type is saved or sent, and the copyable summary is copied to your own clipboard.