ETA From Progress Calculator
Estimate when a job will finish from how long it has already taken and how far along it is — remaining time, total time and a finish clock.
How it works
total time = elapsed ÷ (progress ÷ 100) · remaining = total − elapsed · finish = start clock + total
If a job is a fixed size and your pace holds steady, the fraction complete scales linearly with time: being 40% done after 2 hours implies the whole thing takes 5 hours. The calculator infers your rate from the work already done, projects the remaining time, and adds it to your start clock for a wall-clock finish. It assumes a constant pace, so it is most accurate partway through a uniform task and less so at the very start, when a small elapsed time makes the estimate jumpy.
Worked example
Two hours in and 40% complete means the total is 2 ÷ 0.40 = 5 hours, so 3 hours remain. Starting at 9:00 AM, the finish lands around 2:00 PM.
Frequently asked questions
Why is the estimate unstable early on?
When progress is small, a tiny change in the percent complete swings the projected total a lot — 5% done versus 6% done is a big relative jump. The ETA settles down as you pass roughly a third of the way through.
Does it assume a constant pace?
Yes. It divides elapsed time by the fraction done, which only holds if you keep working at the same rate. For work that speeds up (a learning curve) or slows down (fatigue), treat the result as a rough midpoint.
Can the finish time roll past midnight?
Yes — when the total time pushes the clock past 24:00, the finish time shows a "+1d" (or more) marker so you know it lands on the following day.
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This calculator is for educational purposes. Double-check important results before acting on them.