Marathon Time Predictor & Pace Planner
Estimate your marathon finish time with pace decay or plan your race with split times every 5 km.
※ Use if necessary
Marathon Time Predictor & Pace Planner
Choose a mode to predict your marathon finish time or plan your race with split times every 5 km.
These results are for reference only and were developed for educational and testing purposes. You can also directly access and review the source code, including the logic and free APIs used on this page.
Calculation Results
Marathon Time Predictor & Pace Planner Guide
Estimate your marathon finish time with pace decay or plan your race with split times every 5 km.
How to Use the Calculator
Select a mode and follow the steps below:
Predict Finish Time Mode
- Enter Distance Covered.
- Select Distance Unit (km or miles).
- Select Runner Level (Beginner: 25%, Intermediate: 12%, Elite: 3% decay).
- Enter Elapsed Time.
- Select Marathon Distance or enter a custom distance.
- Click "Calculate".
Target Pace Planner Mode
- Enter Target Finish Time.
- Select Distance Unit.
- Select Marathon Distance or enter a custom distance.
- Click "Calculate".
Understanding Marathon Distances
Full Marathon
42.195 km (26.2 miles).
Half Marathon
21.0975 km (13.1 miles).
Custom Distance
Input any distance for personalized predictions.
Pace Calculation Methods
Predict Finish Time Mode
Uses current pace with decay (25%, 12%, or 3%).
Target Pace Planner Mode
Calculates uniform paces for target time.
Factors Affecting Performance
Fatigue, terrain, and weather can impact times.