About Marathon Pace
Marathon Pace is a simple running calculator for estimating finish times, race pace, and treadmill-to-road pace equivalents.
What it helps with
The calculator is built for runners preparing for full marathons, half marathons, 10K races, and structured treadmill workouts. It focuses on quick answers: how a target pace maps to finish time, and how treadmill speed compares with outdoor road pace.
PaceBib for iPhone
PaceBib (配速尺) brings our pace ruler and race-bib interface to a native iPhone app. Plan race-day splits, share a pace-band image, check your Boston qualifying margin, and convert pace and speed offline.
How to use the numbers
Pace calculations are estimates. Race performance also depends on weather, elevation, course profile, fueling, training history, and recovery. Use Marathon Pace as a planning tool, not as medical, coaching, or performance advice.
Current features
- Marathon, half marathon, 10K, and 5K finish time and pace calculations.
- A slide-rule tape and rolling digits for setting a goal time to the second.
- Race-day splits with even or negative-split pacing, and a printable pace band.
- Metric and imperial pace units.
- Treadmill speed conversion with an outdoor road pace estimate.