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Pace
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min / km
Finish Time
--:--:--
Speed
0.0
kph / mph

Estimated Splits

DistSplit TimeElapsed
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About

Whether you are attempting to break the 4-hour barrier in a marathon or simply tracking your weekly jogs, understanding the relationship between pace, time, and distance is fundamental to endurance training. A precise pace strategy prevents "going out too fast"—a common error that depletes glycogen stores early in a race.

This calculator serves as a digital coach, allowing you to manipulate variables to define your race strategy. By inputting a target finish time for a specific distance (like 21.0975 km for a Half Marathon), you can determine the exact minute-per-mile or minute-per-kilometer pace required to achieve that goal. It also generates a full split table, essential for printing out as a wristband reference on race day.

marathon pace running calculator split calculator race predictor training tools

Formulas

The core logic relies on the relationship between Time, Distance, and Speed (Pace).

Pace = TimeDistance

To convert between metric and imperial units, the following constant is applied:

1 mile 1.60934 km

Reference Data

EventDistance (km)Distance (mi)Beginner PaceElite Pace
5K5.0 km3.1 mi~30-35 min< 14 min
10K10.0 km6.2 mi~60-70 min< 28 min
Half Marathon21.0975 km13.1 mi~2:15 - 2:30< 1:00
Marathon42.195 km26.2 mi~4:30 - 5:00< 2:05
Ultramarathon50.0 km31.07 mi~6:00 - 7:00< 3:00
Ironman Run42.2 km26.2 mi~5:00 - 6:00< 2:40
Cooper TestVariable12 min time2.0 km> 3.5 km
Mile Run1.609 km1.0 mi~8-10 min< 4 min

Frequently Asked Questions

A negative split is a racing strategy where you run the second half of the race faster than the first half. It is generally considered the most efficient way to run long distances because it conserves energy early on. This calculator's split table shows even splits; to plan a negative split, you would aim to be slightly behind the 'even pace' at the halfway mark.
Official race courses are measured along the 'shortest possible route' (tangents). Most runners cannot run perfect tangents due to crowds or weaving, so they often run 1-2% further than the official distance. For a marathon (42.2km), your watch might show 42.6km. You should calculate your pace based on the slightly longer distance to ensure you hit your time goal.
For short intervals (e.g., 400m or 800m repeats), enter the interval distance in the 'Distance' field and your target time. The tool will output the pace. For example, running 400m in 90 seconds equals a 6:00 min/km or 9:39 min/mile pace.
No, this tool calculates pace on a flat surface. As a general rule of thumb, you should add 10-20 seconds per mile to your pace for every 100 feet of elevation gain, though this varies heavily by runner fitness and gradient steepness.