Marathon Pace Calculator
A marathon pace calculator for race day. Enter your goal finish time (42.195 km / 26.2 miles) and get the exact pace you must hold per kilometer and per mile, plus a 5K-by-5K split table so you can check your watch and know instantly whether you are on pace.
Result
| Required pace | |
| Speed |
5K split table
Formula & source
Split at K km = goal seconds × K / 42.195
Source: marathon distance is standardized at 42.195 km (26.2 mi) by World Athletics. Splits are linear interpolation of even pacing — the strategy exercise science associates with the best finish times for non-elites. Unique to this page: the 5K split table is generated from your exact goal time, not rounded to standard goals.
Worked example (you can verify by hand)
Input: goal 4:00:00 (14400 s).
- Required pace: 14400 ÷ 42.195 = 341.3 s/km = 5:41/km
- Per mile: 341.3 × 1.60934 = 549.2 s = 9:09/mile
- 20K split: 14400 × 20 / 42.195 = 6825.6 s = 1:53:46
Expected output: hold 5:41/km; 20K split 1:53:46.
Limitations — what this cannot do
- GPS watches and phone apps typically err by 1–3% on distance; a track-measured time trial is the honest input.
- Hills, heat, altitude and wind change real-world pace — charts assume flat, sea-level, calm conditions.
- Predictions assume similar training and conditions; they are estimates, not guarantees.
- Even splits assume perfect execution — most runners fade 2–5% after 30K; consider banking 10–15 seconds in the first half only if your training supports it.
Disclaimer: Estimates for training planning only, not medical advice. Consult a professional.
FAQ
What is a good marathon goal for a first-timer?
Finishing strong beats a time goal: most first-timers land between 4:00 and 5:30. Pick a pace you held for 32K in training, then add 10–15 s/km.
Should I run even splits or negative splits?
Even pacing is the most reliable strategy for non-elites. Deliberate negative splits require exceptional discipline and usually cost time if mistimed.
How much do hills change my splits?
Rule of thumb: add ~15–20 s/km per 10 m of climbing per km. Adjust the table with your course profile, not just the average.
Why 42.195 km?
The marathon standard was set at the 1908 London Olympics and ratified by the IAAF in 1921 — 26 miles 385 yards, exactly 42.195 km.