Marathon Pace Calculator

Enter your target marathon finish time to see the exact pace per mile, pace per kilometer, and speed you need across the full 26.2 mile (42.195 km) distance.

Quick Facts

Method
Pace = finish time ÷ 26.2188 mi (42.195 km)
A marathon is 42.195 km, equal to 26.2188 miles. Pace is simply total time divided by distance.

Your Results

Calculated
Pace per mile
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Time per mile (26.2188 mi total)
Pace per kilometer
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Time per km (42.195 km total)
Speed
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Average mph / km·h⁻¹
Halfway split
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Even-pace time at 13.1 mi / 21.1 km

Ready

Enter a target finish time and press Calculate.

How marathon pace is calculated

A marathon is a fixed distance of 42.195 kilometers, which is exactly 26.21875 miles (usually written as 26.2 miles). Because the distance never changes, your required pace is a simple division: take your target finish time and divide it by the distance. This calculator does exactly that and reports three equivalent ways of expressing the same effort — pace per mile, pace per kilometer, and average speed — plus the even-pace time you should hit at the halfway mark.

The formulas

  • Pace per mile = finish time ÷ 26.21875 miles
  • Pace per kilometer = finish time ÷ 42.195 km
  • Average speed (mph) = 26.21875 ÷ finish time in hours
  • Average speed (km/h) = 42.195 ÷ finish time in hours
  • Even halfway split = finish time ÷ 2 (reached at 13.1 mi / 21.0975 km)

For example, a 4-hour marathon requires a pace of 9:09 per mile (5:41 per km) and averages 6.55 mph or 10.55 km/h, with an even halfway split of exactly 2:00:00.

Why runners need it

Marathon success is largely an act of pacing discipline. Your body stores only enough glycogen for roughly 90–120 minutes of hard running, so going out even 10–15 seconds per mile too fast in the early miles can drain those reserves and trigger the late-race collapse runners call "hitting the wall" around mile 20. Knowing your exact goal pace lets you program a GPS watch, choose a pace band, or line up with the right pace group so that every mile is deliberate rather than a guess.

Common finish-time reference points

  • 3:00:00 — 6:52/mi · 4:16/km · 8.74 mph (a common competitive amateur goal)
  • 3:30:00 — 8:01/mi · 4:59/km · 7.49 mph
  • 4:00:00 — 9:09/mi · 5:41/km · 6.55 mph (near the global median finish time)
  • 4:30:00 — 10:18/mi · 6:24/km · 5.83 mph
  • 5:00:00 — 11:27/mi · 7:07/km · 5.24 mph

Even pace vs. negative splits

The calculator's halfway split assumes perfectly even pacing. In practice, most experienced runners aim for a slight negative split: running the second 13.1 miles a little faster than the first. Reaching halfway a few seconds behind the even split — say 2:01 rather than 2:00 for a 4-hour goal — leaves a reserve that protects against the slowdown almost everyone experiences in the final 10 kilometers.

Frequently Asked Questions

Is a marathon exactly 26.2 miles?
The official marathon distance set by World Athletics is 42.195 kilometers, which equals 26.21875 miles. "26.2 miles" is the rounded figure. This calculator uses the exact 42.195 km value (26.2188 mi) so pace and speed come out precise to the second.
Should I run the exact pace the calculator gives me?
Treat it as your average target, not a per-mile mandate. Courses have hills, aid stations, and crowds, so individual mile splits will vary. What matters is that your overall average matches the goal pace. Many runners aim to bank the first half a touch slower than the calculated even split to allow for a negative split.
How do heat and hills change the pace I can hold?
This calculator gives the pace required for a given time under ideal conditions; it does not predict what your body can sustain. Heat above about 60°F (16°C) can add roughly 20–30 seconds per mile for every 10°F rise, and significant elevation gain slows most runners. Adjust your target finish time upward on hot or hilly courses rather than expecting to hold flat-course pace.

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