A pace conversion guide, in fifteen languages
How to turn min/km into km/h, min/mi into mph, and one into the other — with a reference table. Plus durations that finally read like durations.
"7 minutes per kilometre — how fast is that?"
That is close to the exact wording people type into a search box before they land here, and until this week the site answered it with a converter and nothing else. There is now a guide at /guides/pace-conversion that answers it properly.
It does not just hand you a formula. It shows where the formula comes from: why 60 divided by your pace gives you km/h, why the mile conversion is a multiplication by 1.609344 rather than a friendly rounding to 1.6, and what changes when you cross between metric and imperial. There is a reference table running from 3:00 to 8:00 per kilometre with the km/h, min/mile and mph equivalent of each row — and every number in it is computed by the same code the converter runs, so the table and the tool cannot drift apart.
It is available in all fifteen languages the site is served in, and it links back to the pace chart and the converter rather than dead-ending.
And times that read like times
A pace of four minutes fifty-two used to appear as 04:52. A three-and-a-half-hour marathon appeared as 03:30:59. Nobody says "zero four fifty-two". The whole site now writes durations the way runners say them: 4:52, 3:30:59, 28:12. The new format comes from calcpace v1.13, the open-source engine that does the arithmetic behind this site, so the library and the website finally write a time the same way.
Two real bugs fell out of that clean-up. The quick calculator used to cap any prediction at 23:59:59, so a very long day came back as a plausible wrong number instead of the right one. And the public athlete pages formatted times in a way that silently wrapped around after a day — a 25-hour ultra was displayed as one hour. Both are fixed.