Discount Damage Calculator

Ten per cent off sounds like ten per cent. It is not, because your costs do not move when you discount, so the whole of it comes out of the profit. On a thirty per cent margin, ten per cent off removes a third of what the job earns and you would need half as much work again to stand still.

This shows both figures side by side at every size of discount: what it costs, and how much more work it would take to replace. The extra work needed is always larger than the discount, at every margin, without exception — that is not an opinion, it is what the arithmetic does.

Then it does the thing that actually changes behaviour: a year of it. Two hundred jobs, forty per cent of them discounted ten per cent, and the total is thousands — given away one entirely reasonable exception at a time. Nobody adds those up, which is precisely why they keep happening.

It also offers the concession worth making instead. Money is the worst thing you can give away: it costs you its full face value and is worth exactly that to them, which is the poorest ratio available. Something that costs you sixty and is worth two hundred and fifty to them leaves you both better off, and the tool checks that what you have in mind actually clears that bar on both sides — because plenty of “added value” costs more than the discount would have.

Save as many versions as you like and put any two side by side, figure against figure, with the better one on each line marked and the difference in its own column. That screen is the one that decides things, and it is the part a free calculator cannot do at all.

It does not say never discount. Sometimes it wins the job and sometimes the job is worth winning. It says know the number first, which is a different and much more useful instruction.

One HTML file. No account, no subscription, no internet needed. Opens on Windows, Mac and Android; the readme explains the extra step on iPhone and iPad, where Apple blocks JavaScript in downloaded files and every tool of this kind is affected.

Everything lives in your browser on your device. Nothing is uploaded, which is why it works offline and why nobody else can see your figures — and it also means clearing your browsing data deletes it. The tool does not pretend otherwise: the header shows how long since your last export at all times, turns amber after three days and red after seven, and export is one click that produces a plain file you keep.