Finish or Stop Calculator

An eighteen thousand pound job. Eleven thousand already spent, six thousand invoiced, nine thousand left to spend.

Finish it and the job loses two thousand. Stop and it loses six and a half.

So finish it — and notice that the eleven thousand already spent played no part in that. It could not have. It is the same number whichever way you go, so it is not a difference between the options, and only differences can decide anything. That is the entire arithmetic of this page and it takes four lines, but almost nobody does it, because doing it means accepting that the earlier money is gone.

It is gone either way. That is the point rather than the objection.

The page prices both options from here forward: what still comes in, what still goes out, and what each leaves you with. It also shows the whole-job result on both, which does not drive the decision but does something more useful — it makes the loss visible on both rows, and it is a great deal easier to accept the smaller of two losses than to accept one in isolation.

It gives the remaining cost at which the answer flips, so you can see how much room there is before carrying on stops being right.

The hours belong in the cost to finish. If completing this ties up capacity you could have sold to somebody else, that is a real cost of finishing and it goes in that box. Leaving it out is the commonest way this sum gets quietly biased towards carrying on.

Reputation is not in here and cannot be. Walking away from a half-finished job has consequences no page can price. What this one will not do is let those consequences stand in as cover for a decision that was actually about not wanting to admit the earlier money was lost — those are two different things, and the arithmetic keeps them apart.

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. This decision comes round more than once, and being able to show somebody the last one is worth something.

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.