Average Speed for a Marathon (42 km) in 3 Hours

Running a full marathon of 42,000 meters in 3 hours (10,800 s) requires an average speed of about 3.89 m/s or 14 km/h.

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How to use this tool

Enter speed, distance and time in the fields above.
Results update instantly as you type — or click Calculate.
Read your speed and the full breakdown beneath it.

Find the average running speed needed to complete a 42 km marathon in 3 hours.

Frequently asked questions

What units should I use?: Any consistent units work — e.g. metres and seconds for SI, or km and hours for everyday driving. Just don't mix (e.g. km/h for speed with metres for distance).
How do I convert km/h to m/s?: Divide by 3.6. Example: 72 km/h ÷ 3.6 = 20 m/s.