Pace tells you how long it takes to cover a unit of distance. It is a helpful way to compare similar runs, but it becomes more useful when you keep terrain, conditions and effort in view.
The simple calculation
Divide the total time by the distance. A 30-minute five-kilometre run is six minutes per kilometre. Speed expresses the same result differently: five kilometres in half an hour is an average of 10 kilometres per hour.
Use the calculator on the SocialGryd Guides page for the arithmetic, then record the route and effort beside the result.
Compare like with like
Hills, wind, surface, temperature, stops and fatigue can all change average pace. A slower number on a harder route does not automatically mean fitness has fallen. Compare repeat routes or similar sessions across several weeks when you want a cleaner signal.
Easy runs should still feel easy
A target pace can be useful, but it should not override how the session is meant to feel. The NHS uses the talk test to describe intensity: at moderate intensity, you can usually talk but not sing. Effort can therefore help explain a pace number rather than compete with it.
Beginners benefit most from building the habit and duration gradually. Pace can wait when chasing it would make the plan harder to repeat.
Sources and further reading
This guide provides general information. Health and exercise needs vary, so seek qualified advice where appropriate.