A Free Tool · Pace, Finish Time & Speed · Miles or Kilometers
What's your running pace?
Enter a distance and a time to get your pace per mile or per kilometer, work backward
from a target pace to a finish time, or find out how far you'll run in a set amount of
time. It's plain arithmetic — pace is time divided by distance — with race
quick-fills for the 5K, 10K, half, and marathon, your speed in mph or km/h, and an
even-pace split table.
Pace, finish time & speed·Miles or kilometers·Per-mile / per-km splits
Read this first
These numbers assume an even pace from start to finish. Real races never hold a
perfectly even pace — hills, wind, heat, and fatigue all shift your splits, and most
runners fade in the back half. Treat the finish-time and split figures as a pacing plan and
a sanity check, not a prediction. When you set a race target, build in a small cushion
rather than planning to run dead even.
Pick what you want to find, choose miles or kilometers, then enter your numbers. Time goes in as HH:MM:SS or MM:SS; pace as MM:SS per unit. Quick-fill a standard race distance if you don't want to type it.
Unit
Quick-fill a race distance
The distance you ran or plan to run, in the unit selected above.
Enter as 1:45:30 for an hour-plus, or 25:00 for minutes and seconds.
Minutes and seconds per unit, e.g. 5:00 for a five-minute pace.
Pace
Finish time
Distance
Speed
Even-pace splits
Marker
Cumulative time
The math, honestly
How pace, time, and speed relate
Everything here is one relationship rearranged three ways. Pace is time
divided by distance:pace = total time ÷ distance. Work
in seconds and your chosen unit, then format the result back to minutes and seconds.
For 5 km in 25:00, that's 1500 s ÷ 5 km = 300 s/km, a
5:00 /km pace.
Flip it to get the other two. Finish time is pace times distance:time = pace × distance. Distance is time divided by
pace:distance = total time ÷ pace. The same three numbers,
whichever one you're missing.
Speed is distance divided by time in hours:speed = distance ÷ (total time ÷ 3600). It's the inverse of
pace and what a treadmill shows. 5 km in 1500 s is
5 ÷ (1500/3600) = 12.0 km/h. The shortcut: 60 ÷ pace
in minutes gives mph or km/h directly.
Standard race distances
The four common road-race distances in both kilometers and miles. These are the exact
figures the quick-fill buttons use — a kilometer is 0.621371 miles, so the mile
values are the metric distances converted.
Race
Kilometersexact
Milesconverted
5K
5
3.10686
10K
10
6.21371
Half marathon
21.0975
13.10938
Marathon
42.195
26.21876
The half marathon and marathon are defined in metric: a marathon is exactly 42.195 km,
and a half is exactly half of that. The mile figures are those distances divided by
1.609344 km per mile.
Example finish times and paces
A few worked finishes computed with the same time-divided-by-distance formula, so they
match what the calculator gives you. Pace is shown per kilometer here; switch the unit in
the tool to see per-mile.
Run
Finish time
Paceper km
Speedkm/h
5K
25:00
5:00 /km
12.0
10K
55:00
5:30 /km
10.9
Half marathon
2:00:00
5:41 /km
10.5
Marathon
4:00:00
5:41 /km
10.5
Pace values are rounded to the nearest second and speed to one decimal. A sub-2:00 half
and a sub-4:00 marathon share almost the same per-km pace — the marathon is just
twice as far, which is exactly why it's so much harder to hold.
Using the result well
A pace number is only useful if you race against it sensibly. Four things worth knowing
before you line up.
Even pace is a model, not a promise
The split table assumes you cover every mile or kilometer in exactly the same time. Almost no real race works that way. Hills, headwind, aid stations, and fatigue all move your splits around. Use the even-pace splits as the line to pace against, then expect reality to wobble on either side of it.
Aim a touch faster than your target
If you want a sub-2:00 half marathon, don't plan to run exactly the 2:00 pace — plan a few seconds per mile faster. That cushion absorbs the slow start through the crowd, the aid-station walk break, and the inevitable late-race fade. Hitting your goal almost always means banking a little time when you feel fresh.
Pace and speed are the same thing, flipped
Your watch shows pace; a treadmill shows speed. They're inverses: 60 ÷ pace in minutes = speed, and 60 ÷ speed = pace. A 10:00 /mi pace is 6.0 mph; a 5:00 /km pace is 12.0 km/h. Knowing the conversion lets you set a treadmill to match an outdoor goal pace without guessing.
Negative splits beat going out hot
Running the second half slightly faster than the first — a negative split — is how strong finishes happen. The opposite, a fast start that turns into a death march, is the most common pacing mistake there is. If the split table tempts you to bank time early by sprinting, resist it; bank effort instead and spend it at the end.
Where to buy
Got your numbers? Here's where to pick up what you need:
The terms behind the calculator, in plain English. These are background definitions to
help you read your own splits, not coaching or training prescriptions.
Pace
How long it takes to cover one unit of distance, written as minutes and seconds per mile or per kilometer (for example 5:00 /km). It's speed turned inside out: a lower pace number means you're running faster. Pace is what most GPS watches display, because it's the number you run against during a race.
Speed
How much distance you cover per hour — miles per hour or kilometers per hour. It's the inverse of pace: 60 ÷ pace in minutes gives speed, and 60 ÷ speed gives pace. Treadmills are set by speed, so this conversion is how you match a machine to an outdoor pace goal.
Finish time
The total elapsed time for the whole distance, which is simply pace × distance. Entered and shown as HH:MM:SS for longer runs or MM:SS for shorter ones. Predicting a finish time from a target pace is the most common reason runners reach for a pace calculator.
Split
The time recorded at a checkpoint — usually each whole mile or kilometer. A cumulative split is the total elapsed time at that marker; the table in this tool shows cumulative even-pace splits so you can glance at your watch and check whether you're on plan.
Negative split
Running the second half of a race faster than the first. It's the hallmark of good pacing and a strong finish. The opposite, a positive split, usually means you started too fast and faded — the most common mistake in distance racing.
Even pace
Covering every unit of distance in the same amount of time. It's the assumption behind this calculator's finish-time and split figures. Real races rarely hold a perfectly even pace because of terrain, wind, and fatigue, so treat even-pace numbers as a target line rather than a forecast.
PR (personal record)
Your fastest-ever time at a given distance, also called a PB (personal best). Pace math is how runners set PR attempts: take the target finish time, divide by the distance to get the required pace, then check it against the split table to see what each mile or km needs to read.
Frequently asked
Pace is total time divided by distance. Convert your finish time to seconds, divide by the distance in your chosen unit, and you get seconds per mile or per km; format that back to minutes and seconds. For example, 5 km in 25:00 is 1500 seconds ÷ 5 km = 300 s/km, a 5:00 /km pace. The same run in miles (3.10686 mi) is 1500 ÷ 3.10686, about 482.8 s/mi, or roughly 8:03 /mi. The calculator converts both ways.
A half marathon is 13.10938 miles or 21.0975 km. To finish under 2 hours (7200 s), divide 7200 by the distance: 7200 ÷ 13.10938 ≈ 549 s/mi, about 9:09 /mi, or 7200 ÷ 21.0975 ≈ 341 s/km, about 5:41 /km. Aim a few seconds per mile faster than that to leave a cushion, since real races rarely hold an exactly even pace. Use the find-finish-time mode to test paces around the target.
Speed is distance ÷ time in hours, the inverse of pace. The quick way: 60 ÷ pace in minutes per mile = mph, and 60 ÷ pace in minutes per km = km/h. A 5:00 /km pace is 60 ÷ 5 = 12.0 km/h. An 8:00 /mi pace is 60 ÷ 8 = 7.5 mph. Watches show pace and treadmills show speed, so this conversion is handy when you move between them.
Multiply your pace by the 5K distance — 5 km or 3.10686 miles. At a 6:00 /km pace, the finish is 6:00 × 5 = 30:00. At a 9:00 /mi pace, it's 9:00 × 3.10686 ≈ 27.96 minutes, about 27:58. Use the find-finish-time mode in the calculator, quick-fill the 5K distance, and enter your pace.
They describe the same effort from opposite directions. Speed (mph or km/h) is distance per hour; pace (minutes per unit) is time per unit. A treadmill set to 6.0 mph equals a 10:00 /mi pace, because 60 ÷ 6 = 10. Higher speed means a lower, faster pace number. This calculator shows both, so you can match a treadmill setting to an outdoor pace target.
An even pace means every mile or km takes the same time — what the split table assumes. A negative split means running the second half faster than the first, a common strategy for a strong finish. A positive split, where you slow down, usually means you went out too fast. The split table is an even-pace reference; treat it as a target to pace against, not a guarantee, since terrain and fatigue shift real splits.
The split table shows the cumulative time you should hit at each whole mile or kilometer if you hold an even pace. If your 10K target pace is 5:30 /km, the table reads 5:30 at 1 km, 11:00 at 2 km, and so on to the finish. Glance at your watch at each marker and compare. Running ahead of the table early is the classic too-fast start; matching or beating it late is a negative split.
No. It's straightforward time-and-distance arithmetic and assumes an even pace throughout. Real races vary with terrain, elevation, heat, wind, and how you fade over the distance, so your actual splits will differ. Use the numbers as a pacing plan and a sanity check, not a prediction, and build in a small cushion against your target rather than planning to run exactly even.
Common mistakes
The calculator assumes a steady, evenly distributed effort. Most errors come from
inputs that don't match that assumption.
Using a training pace instead of a race pace
Easy runs, tempo workouts, and long slow distance are intentionally slower than race pace. If you enter your typical training pace, every output — finish time, target split — reflects a deliberately sub-maximal effort, not your racing capability. For an accurate race estimate, use a recent race result or a flat time-trial effort near your maximum sustainable pace.
Treating the pace as a guarantee on any course
The calculator applies one pace uniformly across the full distance. Real races have hills, turns, weather, and congestion. A 5:30/km pace on a flat road race is a different physical effort than the same pace on a course with 200m of elevation gain. The number is a planning input — not a finish-line promise.
Mixing metric and imperial inputs
Entering a distance in miles but a pace in min/km — or vice versa — is the most common source of wildly wrong outputs. Double-check that your distance unit and pace unit match before reading the result. A pace of 6:00 min/mile and 6:00 min/km are almost four minutes per mile apart.
Using a finish time from a poor race execution
A race where you went out too fast, hit the wall, or finished with a lot left in the tank produces a time that reflects your execution, not your fitness. An even-effort result on a flat course gives the calculator the input it was built for. Outlier races — in either direction — make the output less useful.