Estimate Accuracy Tracker

Everybody knows their jobs run over. Almost nobody knows by how much, which is a shame, because the amount is the only part that is actionable.

Put in your last six to twelve jobs: the hours you quoted, the hours it really took, and what you charged. The tool gives you the number to multiply your future estimates by, and then the more important second number — a safer multiplier at which four jobs in five would come in under, for anybody whose business does not survive a bad one.

It reports the middle job as well as the average, and the difference between them is the point. One catastrophe drags an average and leaves a middle alone, so the average is the wrong figure to price by: it means every future quote carries the memory of one disaster. The tool shows both and says which to use.

It also turns the overrun into the figure that makes it concrete. An overrun is not lost hours, it is a lower hourly rate — you quoted as though the work paid a hundred and twenty an hour and it actually paid a hundred and six. That sentence tends to land harder than a ratio.

Save a set per type of work and compare two. Almost everybody is accurate on one thing and hopeless on another, and an average across both hides exactly the job type that is costing them money.

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 will not make you quicker and it does not know why a job ran over. It tells you by how much, so you can be priced for the speed you actually work at rather than the one you keep meaning to work at. Rough figures are fine — the pattern survives them.

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.