Marathon Pace Calculator
Calculate marathon pace per kilometre, pace per mile, average speed, half-marathon timing and projected splits from 5K through the full 42.195 km marathon.
Build your marathon pace plan
Enter the exact goal time, choose a pacing model and generate a complete checkpoint schedule.
Your marathon pace plan
| Checkpoint | Distance | Target split | Segment pace | Segment focus |
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Marathon pacing rationale
The marathon is not only about goal pace. It is about protecting energy, managing fuel, staying patient early and reaching 30K with enough control to maintain rhythm. Small pace mistakes early can become very large late in the race.
Why even pacing works
Even pacing is usually the safest model for most marathon goals. It limits unnecessary early glycogen use and gives the runner the best chance of maintaining pace after 30K.
Why a slight negative split can work
A slight negative split does not mean jogging the opening half. It means beginning under control, settling into goal effort and gradually increasing pressure through the second half.
Why 30K matters
The 30K checkpoint is one of the most important marathon markers. A runner can feel strong at halfway and still struggle badly after 30K if the opening pace was too aggressive or fueling was poor.
How to use this calculator
- Use pace per kilometre or mile for your watch and race plan.
- Use the 5K and 10K splits to prevent an overly fast start.
- Use halfway to check whether effort remains controlled.
- Use 30K as the real test of marathon execution.
- Use the 35K and 40K splits to prepare for the hardest section.