Price Increase Simulator

There is one number that changes what a small business charges for a year, and almost none of them have ever seen it: how many customers you could lose after a price rise and still earn exactly the same money.

It is usually far more than people expect. On a sixty per cent contribution margin, a twenty per cent rise means a quarter of your customers could walk and leave you level. Everything above that quarter is profit you were not making.

The part that surprises people most is which businesses benefit. A thinner margin gets MORE headroom from a rise, not less: at a ten per cent margin, a ten per cent rise doubles what each sale contributes, so half the customers could go. The businesses with least room to spare have the most to gain, and they are the ones least likely to try it.

The tool uses contribution margin rather than gross or net, which matters. Only the costs a sale actually causes belong in it — materials, subcontractors, fuel — because your rent does not change when you sell one more job, and putting it in makes the headroom look smaller than it is.

It also handles the version most people actually do: raising for new customers only. That reaches a smaller share of the work, and the tool shows how much smaller the benefit is, which is worth knowing before choosing the easier conversation.

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 cannot tell you who will leave or whether your market will bear it. That is judgement and it stays yours. What it settles is the half arithmetic can settle: how much of it you could absorb.

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.