Running Pace Calculator
Last updated: June 11, 2026Pace per km/mile and speed from time & distance.
The Running Pace Calculator works out your exact pace per kilometre and per mile, plus speed in km/h and mph, from any distance and finish time you enter. Type a 5K, 10K, half or full marathon and your goal or actual time, and it instantly divides time by distance for an accurate per-unit pace. It runs fully in your browser, free, with no sign-up and nothing uploaded.
How to use Running Pace Calculator
Use the Running Pace Calculator to turn a distance and a time into a clear pace and speed in seconds. Pick or type your distance, enter the time you ran or are targeting, and choose your units. The tool handles the maths and shows pace per km, pace per mile, and speed side by side so you can read every number at a glance.
Read the full guide: How to Calculate Running Pace (Free Pace Calculator)
- 1Enter your distance, either a preset like 5K, 10K, half marathon (21.0975 km) or full marathon (42.195 km), or a custom figure in km or miles.
- 2Type the finish time as hours, minutes and seconds, for example 00:52:30 for a 10K.
- 3Pick your preferred unit so pace shows per kilometre or per mile, with speed in km/h and mph alongside.
- 4Read the result instantly and adjust the time up or down to see how a faster or slower pace changes your target.
Race-distance presets
Built-in 5K, 10K, half and full marathon buttons use exact official distances like 42.195 km so your marathon pace is never rounded wrong.
Pace and speed together
It shows min/km, min/mile, km/h and mph from a single entry, so you never have to convert between pace and speed by hand.
Instant goal-time checks
Nudge the time field to see exactly what pace a sub-2-hour half or sub-25-minute 5K demands before you commit to it.
Find your marathon goal pace
Enter 42.195 km and your target finish, such as 4:00:00, to see you need roughly 5:41 per km or 9:09 per mile. Lock that number into your long runs and tempo sessions so race-day effort matches a pace you have actually rehearsed, not a guess made at the start line.
Check if a 5K time is realistic
Type 5 km and a goal like 22:30 to reveal the required 4:30/km, then compare it against your recent training paces. Seeing the per-kilometre demand spelled out helps you set a parkrun or race target that is a genuine stretch without being wildly out of reach.
Convert treadmill speed to outdoor pace
If your treadmill shows km/h or mph but your plan lists pace, enter a fixed distance and the time it took at that speed to translate it into min/km and min/mile. This lets you match indoor sessions to outdoor pace targets when winter or weather forces your runs inside.
Plan even splits for a half marathon
Put in 21.0975 km and a sub-2-hour goal of 1:59:00 to get about 5:38 per km, then use that figure to hold steady splits through each kilometre marker. Knowing the exact pace stops you starting too fast and fading over the closing miles of the race.
Running Pace Calculator — frequently asked questions
How is running pace calculated?
Pace equals total time divided by distance. For a 30-minute 5K, that is 30 minutes divided by 5 km, giving 6:00 per kilometre. The tool keeps the seconds remainder and formats it as minutes and seconds rather than a decimal.
How do you convert pace per km to pace per mile?
Multiply your per-kilometre pace by 1.609344, since one mile equals 1.609344 km. A 5:00/km pace becomes about 8:03 per mile. The calculator does this conversion automatically when you switch units.
How is speed in km/h worked out from pace?
Speed in km/h is 60 divided by your minutes per kilometre. A 6:00/km pace is 60 / 6 = 10 km/h. For mph it uses 60 divided by minutes per mile, so the two speeds always match your two paces.
Is this pace calculator accurate for a marathon?
Yes. It uses the exact marathon distance of 42.195 km (26.219 miles) and the half marathon of 21.0975 km, so your goal pace reflects the real course length instead of a rounded 42 km or 21 km.
Is my data private when I use this tool?
Completely. Every calculation runs in your browser using JavaScript, so your distances and times are never uploaded to a server, stored, or shared. There is no sign-up and no account needed.
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