Discount Impact Calculator

A discount is taken off the price, but it is paid out of the profit, because your cost does not change when you drop the number. Take ten percent off a job priced at 4,500 with a thirty percent margin and you have not given away a tenth of anything. You have given away a third of what you were going to keep.

The volume figure answers one question: how much extra work would you have to sell at the lower price to end the year with the same gross profit? It comes from the discount divided by what is left of the margin after the discount. That is why a small-looking discount on a thin margin turns into a very large amount of extra work, and why the number climbs so fast.

The common mistake is comparing the discount to the price instead of to the margin. Once the discount reaches your margin there is no answer at all. You are handing over everything you were going to keep, and past that point every job you win costs you money to finish. Selling more of them makes the year worse rather than better.

Two numbers decide all of this: the price, and either the margin you price at or what the job actually costs you. If the cost is a guess, so is everything on this page. Zeus keeps each job with its own quote, invoice, expenses and receipts on the job record, so the cost you feed into a decision like this is one you look up instead of one you remember.