Running Pace Calculator

Pace is the single most useful number in running. It tells you how hard you are working, whether your training is on track, and exactly what you need to hold on race day to hit a target time. This calculator solves for any one of pace, distance or time when you know the other two, then goes further — predicting your finish times at other race distances and generating the training pace zones you should be running in day to day. Everything works in both kilometres and miles, and nothing needs an account.

Pace, Distance, and Time

Distance (km)Total Time (MM:SS or HH:MM:SS)Pace (MM:SS per km)

Preview

Race Time Predictor

Who is this calculator for?

This calculator is built for anyone who needs a number rather than a guess. Parkrunners checking whether a sub-25 is realistic, club runners building a race strategy around even splits, first-time marathoners working out what pace their training actually supports, coaches setting session paces for a squad, and treadmill runners converting a speed setting into a per-mile pace. If you are training by feel and want to sanity-check what that feel translates to, this is the fastest way to do it.

How it works

The core calculation is simple division: pace = total time ÷ distance. Run 10 km in 50 minutes and your pace is 5:00 per kilometre, or 8:03 per mile. The calculator handles the unit conversion for you, so you can enter a distance in kilometres and read the result in minutes per mile without doing the 1.609 conversion yourself.

Working the other way is just as useful. If you know the pace you want to hold, the calculator multiplies it by the distance to give your finish time. This is how most runners plan a race — decide on a realistic target pace, check what finish time it produces, then adjust until the two feel achievable together.

Race time prediction uses the Riegel formula, published by Peter Riegel in 1977 and still the most widely used endurance prediction model. It takes a known performance at one distance and projects it to another using an endurance exponent of 1.06, which accounts for the fact that you cannot hold 5K pace for a marathon. It is accurate to within a few percent for runners with a reasonable aerobic base, though it tends to be optimistic about the marathon if your long runs have been short.

Training pace zones are derived as percentages of threshold pace. Easy runs sit at 70–75% of threshold effort, long runs at 75–80%, tempo work at 85–90%, and interval sessions at 95–100%. Most recreational runners run their easy days too fast and their hard days too slow, which is why having the actual numbers in front of you matters.

Worked examples

Find your pace from a finished run

Inputs: Distance: 10 km, Time: 52:30

Pace: 5:15/km (8:27/mile). Projected half marathon: ~1:56:30, marathon: ~4:02:00.

Work out the time for a target pace

Inputs: Distance: 21.1 km, Pace: 5:30/km

Finish time: 1:56:03. Easy run pace from this: roughly 6:45–7:15/km.

Convert between km and mile pace

Inputs: Pace: 4:45/km

Equivalent: 7:39/mile. Over a marathon this gives a finish time of about 3:20:20.

Predict a marathon from a recent 10K

Inputs: Distance: 10 km, Time: 45:00

Riegel projection: half marathon ~1:39:45, marathon ~3:27:50. Treat the marathon figure as a ceiling rather than a target unless your long runs support it.

Frequently asked questions

How do I calculate running pace?

Divide your total run time by your distance. If you run 10K in 50:00, your pace is 5:00 per kilometer.

Can I switch between miles and kilometers?

Yes. The calculator converts pace and distance between kilometers and miles while keeping your workout effort equivalent.

What is a good beginner running pace?

A good beginner pace is one where you can hold a conversation. For many runners this is often between 6:00 to 8:00 per km.

What is the race time predictor based on?

The predictor uses the Riegel formula, which estimates future race times from your recent performance and race distance.

How should I use training pace zones?

Use easy pace for recovery, marathon pace for long efforts, threshold for tempo sessions, and interval/repetition for speed sessions.