1. What is the Marathon Pace Calculator?

The Marathon Pace Calculator estimates your marathon pace based on your current 5K race pace using a mathematical model that accounts for the relationship between different race distances.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( P_{mar} \) — Predicted marathon pace (min/mile)
• \( P_{5k} \) — Your current 5K pace (min/mile)
• \( D_{mar} \) — Marathon distance (26.2 miles)
• \( D_{5k} \) — 5K distance (3.1 miles)
• \( k \) — Exponent (typically ≈1.06)

Explanation: The formula accounts for the fact that pace slows non-linearly as race distance increases. The exponent k represents how quickly your pace deteriorates with distance.

3. Importance of Pace Prediction

Details: Accurate pace prediction helps runners set realistic marathon goals, plan training paces, and develop race strategies to avoid hitting the wall.

4. Using the Calculator

Tips: Enter your current 5K pace in minutes and seconds per mile. The default exponent of 1.06 works for most runners, but you can adjust it based on your personal endurance characteristics.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this prediction?
A: It provides a reasonable estimate for well-trained runners. Actual marathon performance depends on training, course difficulty, and race conditions.

Q2: Should I use my PR or current fitness 5K time?
A: Use your current fitness level. If you haven't raced recently, use a time trial or estimate based on recent workouts.

Q3: Why does the exponent k matter?
A: Runners with better endurance (ability to maintain pace over distance) will have lower k values (closer to 1.0), while those who fatigue quickly will have higher values.

Q4: Can I use this for other distances?
A: Yes, the same formula works for predicting any longer distance pace from a shorter one, though the optimal k value may vary.

Q5: How should I adjust for hilly courses?
A: Add 2-5% to your predicted pace for hilly courses, depending on the elevation profile.