Pace Calculator: Pace, Time and Distance

Time at each marker, assuming the same pace throughout
Marker	Split	Elapsed
1 km	0:05:00	0:05:00
2 km	0:05:00	0:10:00
3 km	0:05:00	0:15:00
4 km	0:05:00	0:20:00
5 km	0:05:00	0:25:00
6 km	0:05:00	0:30:00
7 km	0:05:00	0:35:00
8 km	0:05:00	0:40:00
9 km	0:05:00	0:45:00
10 km	0:05:00	0:50:00

Finish times for common race distances at your pace
Race	Distance	Finish time
5K	5 km	0:25:00
10K	10 km	0:50:00
Half marathon	21.0975 km	1:45:29
Marathon	42.195 km	3:30:59

How this calculator works

10 km in 0:50:00 is a pace of 5:00 per km, or 8:03 per mile.

Step 1Pick the unknownPace, time or distancechoose the one you want to find
Step 2Enter the other two10 km, 0:50:00in the units you prefer
Step 3Read the answer5:00 per kmwith speed, splits and race times

Pace is time divided by distance. Speed is distance divided by time. Each is the reciprocal of the other, so one can always be turned into the other. The calculator converts everything to metres and seconds first.

What the figures assume

Even paceSplits and race times assume you hold one steady pace from start to finish.
Exact mileOne mile is taken as exactly 1,609.344 metres, the international mile.
Display roundingFull precision is kept inside; only the shown times are rounded to the nearest second.

Worked example

10 km in 0:50:00

Pace: pace = time ÷ distance
Speed: speed (km/h) = 3,600 ÷ pace (seconds per km)
Per mile: pace per mile = pace per km × 1.609344

timetotal time in seconds 3,000
distancedistance in km 10
1 milemetres in a mile 1,609.344

Pace per km3,000 s ÷ 10 km5:00 per km
Pace per mile300 s × 1.6093448:03 per mile
Speed3,600 ÷ 30012.00 km/h
Speed in mph12 ÷ 1.6093447.46 mph

At this pace a half marathon takes 1:45:29 and a marathon 3:30:59. Figures are rounded to the nearest second for display.

Reading your result

Solve for time0:27:305 km at 5:30 per km.
Solve for distance12 kmOne hour at 5:00 per km.
Solve for pace5:00 per km10 km in 0:50:00.

All three use the same two-input rule: choose what to solve for and give the other two.

Split rows show elapsed time at each marker. If the distance is not a whole number of markers, a shorter last row ends exactly at the finish. A 400 m split table suits a track session.

Rounding carries into the next minute. A pace of 59.99 seconds per km is shown as 1:00, never as 0:60.

Speed, distance and energy

Pace is time per kilometre or mile; speed is the same thing turned around. Other tools cover the rest of a training plan.

For speed or travel time on any trip, try the speed calculator. To estimate the energy a training day needs, the BMR and TDEE calculator includes activity levels, and the protein intake calculator covers daily protein.

Common mistakes

Mistake: Mixing kilometre pace with a distance in miles.
Instead: Choose the pace unit and the distance unit separately; the calculator converts for you.
Mistake: Typing 5.30 to mean 5 minutes 30 seconds.
Instead: Use the minutes box for 5 and the seconds box for 30.
Mistake: Expecting an even pace over a whole race.
Instead: Treat the splits as a plan, since hills, heat and fatigue change your pace.

This calculator only does arithmetic on the numbers you enter. It gives no training or health advice, so ask a coach or a qualified healthcare professional about how hard to train.

Checking the method

A separate script recomputes every test case two ways, in exact fractions and through speed, using the exact international mile.

Read how we test our calculators, or browse more health calculators.

Frequently asked questions

What is pace?

Pace is the time taken to cover one unit of distance, usually a kilometre or a mile. A lower pace number means faster movement. Speed is the reverse: distance covered per hour.

How do I convert pace per km to pace per mile?

Multiply the time per kilometre by 1.609344, because a mile is exactly 1,609.344 metres. For example, 5:00 per km is about 8:03 per mile.

How is speed worked out from pace?

Divide 3,600 seconds by the pace in seconds per kilometre to get km/h. Divide 3,600 by the pace per mile to get mph.

Why can the displayed seconds differ slightly from my input?

The calculator keeps full precision and rounds only what it shows, to the nearest whole second. A pace of 4:59.6 therefore appears as 5:00.

What do the split times show?

They show the elapsed time at each marker if you hold the same pace from start to finish. If the distance is not a whole number of markers, a shorter final row ends at the finish.

Which distances are used for the race times?

A 5K is 5 km, a 10K is 10 km, a half marathon is 21.0975 km and a marathon is 42.195 km, the official road-race distances.

Will I really hold the same pace in a race?

Probably not exactly. Hills, heat, wind, crowds and fatigue all change pace. Treat the table as an even-pace plan rather than a prediction.

Does this give training or health advice?

No. It only does arithmetic on the numbers you enter. Ask a qualified coach or healthcare professional about training load and your health.

Sources and methodology

The formulas are standard time-value-of-money results. We check every figure against golden values worked out independently, by closed form and by month-by-month simulation; see the methodology.

NIST Guide to the SI, Appendix B.8: Factors for units listed by kind of quantity, National Institute of Standards and Technology (accessed 22 Oct 2026)
Book of Rules, World Athletics (accessed 22 Oct 2026)

Written and maintained by Nitin Raturi, a software engineer (about the author). Last reviewed 22 Oct 2026; next review due by 22 Oct 2027. Found an error? Tell us.

Changelog

22 Oct 2026: Registered at the owner's request. Solves pace, time or distance with splits and race times; 10 km in 0:50:00 gives 5:00 per km.