I keep doing the same calculation over and over again, so I decided to make an online tool specially for it:

>>> Linear time calculator <<<

It’s a simple enough calculation to work out a time estimate for something based on progress so far (assuming progress has a number). Could be used for anything I suppose, but I keep doing this for long-running data processing scripts, where a count is being spat out to a log file e.g. a count of records processed.

Here’s how the tool looks for script I was running recently.

Alternatives

Maybe I should’ve just worked out how to do the time format conversion and arithmetic properly in a spreadsheet, but why use a spreadsheet when you can build a whole dedicated tool for the job?!

There are some similar existing online calculators. You can do the time between two date times on timeanddate.com which I suppose is the error prone part.

Various online calculators do a speed calculation (division!) If you imagine “miles per hour” is “records per hour” it works.