Pace Half Marathon Calculator
Half Marathon Pace Calculator works out Pace and Pace per mile from Solve for, Application and Distance. The default figures on this page give finish time of 6,962.175 s; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
5 steps
- Distance = 21.0975 km (13.1094 miles).
- Elapsed time = 6962.175 s (1:56:02.18).
- Pace = time / distance = 6962.175 / 21.0975 = 330 s per km.
- Pace per mile = 330 x 1.609344 = 531.084 s.
- Speed = distance / hours = 21.0975 / (6962.175 / 3600) = 10.9091 km/h.
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Keep this result
Save it, change one figure, then compare the two
The calculation stays free. Save this scenario, adjust one assumption, save that too, and put them side by side to see exactly what the change costs you. A free account keeps 5 scenarios and 2 comparisons; Personal makes both unlimited and adds exports and private links. Nothing is saved unless you press Save.
What the Half Marathon Pace Calculator calculates
Solves pace, finish time or distance from any two of them, and prints average speed and an even-effort split table for the course.
How to use this Half Marathon Pace Calculator
Enter Solve for, Application, Distance and Distance (miles). Pace updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Pace, Pace per mile and Pace per kilometre.
The method follows OpenStax Elementary Algebra 2e, proportional relationships (rate = quantity per unit), NIST Special Publication 811, international mile = 1.609344 km exactly and World Athletics Competition Rules, standard road race distances (marathon 42.195 km).
What you can compare
Change one input at a time to see how it affects Pace, Pace per mile and Pace per kilometre. The inputs you can vary are Solve for, Application, Distance, Distance (miles), Duration and Duration (h:mm:ss).
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
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Frequently asked questions
How do I calculate my pace for a half marathon?
Solves pace, finish time or distance from any two of them, and prints average speed and an even-effort split table for the course. Open “How this is worked out” beside the result to see each step for your own figures.
Is 2.5 hours slow for a half marathon?
Solves pace, finish time or distance from any two of them, and prints average speed and an even-effort split table for the course. On the figures this page opens with — distance 5 km and duration 1,500 s — the finish time is 6,962.175 s. Put your own figures in their place and the working updates beside the result.
What's a good running pace for a half marathon?
Solves pace, finish time or distance from any two of them, and prints average speed and an even-effort split table for the course. On this page it is computed from Solve for, Application and Distance and shown as Pace, Pace per mile and Pace per kilometre.
How fast is a 2 hour 30 minute half marathon?
It needs Solve for, Application, Distance, Distance (miles), Duration and Duration (h:mm:ss). Nothing else is required, and the figures stay in your browser.
What information do I need for the Half Marathon Pace Calculator?
You need Solve for, Application, Distance, Distance (miles), Duration, Duration (h:mm:ss), Pace and Pace (mm:ss). The page opens with default figures that give finish time of 6,962.175 s, so you can see the scale before entering your own.
What does this Half Marathon Pace Calculator show?
It shows Pace, Pace per mile, Pace per kilometre, Average speed, Speed, Finish time, Distance and Split table, with the working and any warnings for your entries.