Pace Calculator: Running, Walking, Cycling, Swimming and Rowing

How to use this tool

Pick what you want to find, fill in the other two boxes and the answer appears at the top. Find time is the default: give it a pace and a distance and it tells you the finish time. Find pace takes a distance and a time, which is the question after a race or a parkrun. Find distance takes a pace and a time, which is the question when you have an hour and want to know how far it gets you. The distance list holds every standard race from 100 m to 100 miles, and Another distance lets you type any figure in kilometres, miles, metres or yards.

The cards show the same pace per mile, per kilometre, per 100 metres, per 100 yards and per 500 metres, with the speed in km/h, mph and metres per second. The mph card is the treadmill number: treadmills are set in miles or kilometres per hour, not in pace, and the conversion is the one people search for most. Tap any card to copy it.

Below that the tool plans the race. The split table gives the pace and the running clock at every mile or kilometre, and the split plan control shapes it: even, or a negative split of 1 to 3 percent where the second half is faster, or a positive split if you want to see the damage. The chart draws the same thing, teal bars for the pace of each split and a blue line for the clock. The equivalent distance table uses the Riegel formula to ask what the same fitness is worth at every other race distance, and the training band table works backwards to the paces you would train at, anchored to the 5K time this performance implies.

The input people most often get wrong is the pace unit. A 5:00 pace means very different things per mile and per kilometre, an 18 percent difference, and if the answer looks a fifth out, that is why. The other trap is entering a training pace and then reading the equivalent distance table as a prediction; it only means anything if what you entered was a genuine race effort. Every chip and table row is a link with its own address, and the exports carry your numbers and nothing else.

What the calculation is doing

Pace, time and distance are one equation with three terms. Time equals pace multiplied by distance, so pace equals time divided by distance and distance equals time divided by pace. Fix any two and the third is not estimated or modelled, it is settled, and this tool does that arithmetic in seconds internally so that nothing accumulates rounding. The only care needed is with units: a pace is minutes per some unit of distance, so the distance has to be expressed in that same unit before you multiply. A half marathon is 21.0975 km or 13.1094 miles, and at 8:00 per mile the multiplication is 13.1094 × 480 seconds, which is 6,292.5 seconds, 1:44:53.

Speed is the same information upside down. Pace is time per unit distance and speed is distance per unit time, so one is the reciprocal of the other, and the shortcut worth memorising is that miles per hour equals 60 divided by the minutes per mile. A 10 minute mile is 6 mph, an 8 minute mile is 7.5 mph, a 6 minute mile is 10 mph. In metric it is the same shape: km/h equals 60 divided by the minutes per kilometre, so 5:00 per kilometre is 12 km/h. That reciprocal is why pace improvements get harder as you get faster: going from 10:00 to 9:00 per mile buys you 0.67 mph, while going from 5:00 to 4:00 buys you 3 mph and almost nobody ever does.

Why pace feels linear and speed does not

Runners think in pace and machines think in speed, and the two disagree about what a minute is worth. Take a minute off a 12 minute mile and you are 9 percent faster. Take a minute off a 6 minute mile and you are 20 percent faster. The same minute, twice the gain, because pace is a reciprocal and reciprocals compress at the fast end. This is behind the shape of every race result distribution: the gap between the winner and the tenth finisher is a handful of seconds per mile, and the gap between the middle and the back of the field is minutes.

It is also why treadmill speed is the more honest number for comparing efforts. Two runners at 9:00 and 8:00 per mile look a minute apart; as speeds they are 6.67 and 7.5 mph, which is 12 percent, the same relative gap as 6:00 against 5:21. If you are tracking improvement over a season, watch the speed rather than the pace and the progress curve will tell you the truth rather than flattering you at the slow end and discouraging you at the fast end.

Even splits, negative splits and going out too fast

An even split means every mile at the same pace. A negative split means the second half faster than the first, and a positive split means the second half slower, which is what happens to most people whether they planned it or not. The split plan control builds any of the three, spreading the drift smoothly across the race so that a 2 percent negative split starts about 1 percent slower than average and ends about 1 percent faster, with the finish time unchanged.

The case for planning a small negative split is asymmetry, not physiology. Start one percent slow over a marathon and you lose about two minutes in the first half, most of which you get back. Start three percent fast and the last 10 km can cost twenty minutes or more, because you run out of stored carbohydrate rather than simply slowing. The best marathon performances at every level cluster around even or slightly negative, and the wreckage clusters on the positive side. Set the plan to positive 2 percent once and look at what the final splits become; it is a more persuasive argument than any advice.

Two practical notes. Road races are measured along the shortest legal route, so unless you run every tangent perfectly your watch will read long, typically 1 to 2 percent over a marathon, and your watch pace will look slower than your official pace; plan a few seconds a mile inside the target to absorb it. And hills, wind and heat all move pace without moving effort, so on a rolling course use the split plan for the flat sections and treat the climbs as a time budget rather than a pace target.

Treadmill speed, incline and why the numbers differ

Treadmills are set in miles or kilometres per hour, so the conversion is the reciprocal above: 60 divided by the minutes per mile gives mph, 60 divided by the minutes per kilometre gives km/h. An 8 minute mile is 7.5 mph, a 9 minute mile is 6.7, a 10 minute mile is 6 and a 7 minute mile is 8.6. The tool shows all three speed figures for whatever pace you enter, so a session written as pace can be dialled straight into a machine.

The usual complaint is that treadmill running feels easier than the same speed outdoors, and there are two real reasons and one myth. The real ones are air resistance, which is absent indoors and costs a few percent of energy outdoors at ordinary speeds, and belt assistance, which is small on a good machine and larger on a worn one. Setting 1 percent incline is the standard compensation and comes from a 1996 study that found it matched outdoor oxygen cost at paces faster than about 8 minutes per mile; below that speed the correction is smaller and mostly unnecessary. The myth is that the belt pulls your legs through for you; it does not, though a poorly calibrated machine can easily be running 3 to 5 percent off its display, which is worth checking against a known distance before you trust a treadmill time.

What the same effort is worth at another distance

The equivalent distance table uses the formula Peter Riegel published in 1977: the predicted time equals the known time multiplied by the ratio of the distances raised to the power 1.06. The exponent says that pace slows by about 6 percent every time the distance doubles, which turns out to fit trained runners remarkably well from about 1,500 m up to the half marathon. A 20 minute 5K maps to a 41:42 10K and a 1:32:00 half, and those figures hold up against real result sets.

Beyond the half it runs optimistic, and you should know why before you believe it. The formula only knows about the distance ratio; it has no idea whether you have run a 20 mile long run or whether you can absorb enough carbohydrate to finish a marathon without running out. A 20 minute 5K predicts a 3:11 marathon, which is achievable for someone doing 60 miles a week and fanciful for someone doing 20. Treat the marathon row as the best case if everything else in your training is in place, and note that the training band table on this page is anchored to the 5K equivalent rather than to the marathon row for exactly that reason.

A worked check you can repeat on paper

Start with the default, a half marathon at 8:00 per mile. A half marathon is 21,097.5 metres and a mile is 1,609.344 metres, so the race is 21,097.5 ÷ 1,609.344 = 13.1094 miles. At 8 minutes each that is 104.875 minutes, which is 1 hour 44 minutes and 52.5 seconds, displayed as 1:44:53. In metric, 8:00 per mile is 480 × 1000 ÷ 1609.344 = 298.26 seconds per kilometre, 4:58, and 21.0975 × 298.26 = 6,292.5 seconds, the same answer by the other route.

Now the reverse, a 5K in 25:00. That is 1,500 seconds over 5 kilometres, so 300 seconds or 5:00 per kilometre, and 300 × 1.609344 = 482.8 seconds per mile, 8:03. As speed, 5 km in 1,500 s is 3.333 m/s, 12 km/h, 7.46 mph. And the third question: an hour at 5:00 per kilometre is 3,600 ÷ 300 = 12 kilometres, 7.46 miles.

Finally a split plan. A 25:00 5K on even splits is five kilometres of 5:00 with the clock reading 5:00, 10:00, 15:00, 20:00 and 25:00. On a 2 percent negative split the same race becomes 5:02, 5:01, 5:00, 4:59 and 4:58, still finishing at exactly 25:00, with the first kilometre two seconds slower than average and the last two seconds faster. The tool shows the same five rows, so if your arithmetic differs, check whether you are dividing the drift across the whole race or applying it to each half.

Mistakes that catch people out

Mixing the pace unit with the distance unit. A 5:00 pace per kilometre is not a 5:00 pace per mile; they are 18 percent apart. Check the unit next to the pace box before you trust the answer.

Reading a race prediction as a plan. Riegel from a 5K tells you what your speed is worth if everything else is in place. Over the marathon it usually is not, and the table is a ceiling rather than a target.

Setting the treadmill to your outdoor pace and expecting the same effort. Add 1 percent incline at paces under 8 minutes per mile, and check the belt against a known distance before you believe a treadmill personal best.

Chasing an average pace that is already lost. If you are 90 seconds down at halfway in a marathon, making it back costs roughly twice that in effort over the second half. Reset to the new realistic target rather than running the first plan into the ground.

Planning to watch pace rather than official pace. Your watch will read the course long. Over a marathon a 1.5 percent overread turns a 4:00:00 plan into a 4:03:30 finish if you pace by the watch alone.

Treating 100 yard and 100 metre swim paces as the same. A yard is 8.4 percent shorter, so the same number per 100 is a meaningfully slower swim in yards. Pick the right unit before comparing pool times.

Pace, speed and finish time at a glance

The table below is exact arithmetic for the common running paces. Each pace in the first column opens the calculator on that pace over a marathon, and every other figure follows from it.

Popular pace questions

The paces and finish times people look up most. Each opens the calculator on that combination with its own address, so you can bookmark or share the exact answer.

Minutes per mile over the common races

Minutes per kilometre over the common races

Finish times to pace

The mile, the 5 mile and the track distances

Walking, and the long stuff

Swimming and rowing

How this was checked

The engine was tested in Node before the page was built. The identity was checked first in both directions: 8:00 per mile returns 4:58 per kilometre, 12.070 km/h and exactly 7.5 mph, and converting back returns 480 seconds to the nanosecond. A half marathon at 8:00 per mile returns 1:44:53 and a marathon 3:29:45, which match the arithmetic 13.1094 × 8 and 26.2188 × 8 done by hand. A 5K in 25:00 returns exactly 5:00 per kilometre and 8:03 per mile, and an hour at 5:00 per kilometre returns exactly 12,000 metres. The time parser was tested against 8:00, 1:45:30, bare seconds and a decimal split, and it rejects 1:70, empty strings, letters and four part times rather than guessing.

The split builder was checked to conserve the total: a 2 percent negative split over a 5K returns 5:02, 5:01, 5:00, 4:59 and 4:58, which sums to exactly 25:00, and part splits at the end of a half marathon or marathon carry the right fraction of a mile. The Riegel output was checked against published tables, where a 20 minute 5K gives 41:42 for 10K, 1:32:00 for a half and 3:11:49 for a marathon. The training bands are anchored to the 5K time the entered performance implies rather than to the entered pace itself, so entering a marathon pace returns a marathon band that brackets what you typed. The live page was then opened at every address linked above and each was checked for a distinct title, the right headline, a scale and chart that rendered, and clean CSV, image and print output containing only that value, on a desktop and a phone width screen.

Common questions

How do you calculate running pace?

Divide your time by your distance. A 5K in 25 minutes is 1,500 seconds over 5 kilometres, which is 300 seconds or 5:00 per kilometre, and 8:03 per mile. Going the other way, multiply pace by distance: 8:00 per mile over a half marathon is 13.1094 × 8 minutes, which is 1:44:53. The one thing to watch is that the pace and the distance are in the same unit, because mixing minutes per mile with kilometres is the commonest error on any pace question.

What is an 8 minute mile in kilometres and on a treadmill?

8:00 per mile is 4:58 per kilometre, 12.07 km/h and 7.5 mph. The treadmill number is the easy one: divide 60 by the minutes per mile, so 60 ÷ 8 = 7.5 mph. A 10 minute mile is 6 mph, a 12 minute mile is 5 mph and a 6 minute mile is 10 mph. At 8:00 per mile a 5K takes 24:51, a 10K 49:43, a half marathon 1:44:53 and a marathon 3:29:45.

What pace do I need for a sub 4 hour marathon?

9:09 per mile, or 5:41 per kilometre, which is 10.55 km/h. For a sub 5 hour marathon it is 11:27 per mile or 7:07 per kilometre; for sub 3:30 it is 8:00 per mile or 4:58 per kilometre; and for sub 3 hours it is 6:52 per mile or 4:16 per kilometre. Aim a few seconds a mile inside the target rather than exactly on it, because almost every road marathon measures slightly long on a watch once you have run the tangents imperfectly.

What is a negative split and is it worth planning?

A negative split means running the second half faster than the first. The split plan control here builds one for you at 1, 2 or 3 percent, so a 2 percent negative split over a marathon starts about 1 percent slower than average pace and finishes about 1 percent faster. Most marathon world bests have been run close to even or slightly negative, and for everyone else the value is mostly insurance: starting one percent slow costs a minute or two, and starting three percent fast can cost twenty.

How accurate is predicting a race time from another distance?

The equivalent distance table uses the Riegel formula, time two equals time one multiplied by the distance ratio raised to the power 1.06, which is a good fit between about 1,500 m and the half marathon for a trained runner. Beyond the half it runs optimistic, because the marathon is limited by fuel and by how many long runs you have done rather than by raw speed. Treat a Riegel marathon prediction from a 5K as a ceiling, not a target, unless your weekly mileage genuinely supports it.

How do I convert swimming or rowing pace?

Swimming is quoted per 100 metres or per 100 yards and rowing per 500 metres, and both are on the pace unit list, so a 2:00 per 500 m erg pace converts straight to 6:26 per kilometre and 24 seconds per 100 m. Set the activity to swimming or rowing and the splits and equivalent distances are labelled for that sport. A 100 yard pace is 8.4 percent faster than the same number per 100 metres, because a yard is shorter than a metre, which is why pool records from 25 yard pools look quicker than they are.

Related Calculators and Reference

• One Rep Max Calculator: turns any set into an estimated 1RM with all seven published formulas, and back into working weights with the plates for each.
• TDEE Calculator: daily calorie burn and the intake for a cut or a gain, which is where a step count or a training week turns into a diet.
• Steps to Miles Converter: a step count turned into miles or kilometres using your own step length, before you bring the distance here for a pace.
• Speed Converter: km/h, mph, knots, metres per second and Mach, when you want the speed rather than the pace.
• Time Unit Converter: seconds, minutes and hours with whole unit breakdowns, for the training week behind the race.
• Length Converter: metres, kilometres, feet and miles, the distances every pace is measured against.
• Date Difference Calculator: how many weeks are left until race day, and how many long runs fit into them.
• Temperature Converter: race day heat in both scales, since pace slows measurably above about 15 °C.
• Percentage Calculator: for the split percentages and the week to week mileage increases behind a training plan.
• Water Intake Calculator: how much to drink a day, with extra for exercise and heat.
• Heart Rate Zone Calculator: training zones from your age.
• Calories Burned Calculator: calories burned at your pace.
• Wind Chill Calculator: the wind chill for a winter run.
• Humidex Calculator: the humidex before a summer run.
• Speed Distance Time Calculator: distance, time or speed in any unit, with arrival times.
• VO2 Max Calculator: VDOT and VO2 max from a race time, the Daniels method to compare with Riegel.
• Hiking Time Calculator: find your own flat pace before choosing a pace preset.
• World Athletics rules and regulations: the official race distances and the course measurement rules that decide what your watch is disagreeing with.