1. What is the 10K to Half Marathon Prediction?

This calculator predicts your half marathon time based on your 10K race performance using a well-established mathematical model that accounts for the increased distance and fatigue factors.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( T_{half} \) — Predicted half marathon time (minutes)
• \( T_{10k} \) — Your 10K race time (minutes)
• \( D_{half} \) — Half marathon distance (13.1 miles)
• \( D_{10k} \) — 10K distance (6.2 miles)
• \( k \) — Exponent (typically ≈1.06)

Explanation: The formula accounts for the non-linear relationship between race distance and time, as running pace typically slows as distance increases.

3. Importance of Race Time Prediction

Details: Accurate race time prediction helps runners set appropriate pace goals, plan training programs, and estimate finish times for race registration.

4. Using the Calculator

Tips: Enter your recent 10K race time in minutes. The default exponent (1.06) works for most runners, but you can adjust it based on your experience (higher values for less endurance-trained runners).

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this prediction?
A: For well-trained runners, predictions are typically within ±5% of actual times, assuming similar conditions and training.

Q2: Should I use my PR or recent 10K time?
A: Use your most recent 10K time that reflects your current fitness level, not necessarily your personal best.

Q3: Why does the exponent k vary?
A: The exponent accounts for endurance capabilities. More endurance-trained runners may use values closer to 1.04, while less trained runners may use up to 1.08.

Q4: Can I use this for marathon prediction?
A: No, this formula is specifically designed for half marathon prediction from 10K times. Different models exist for marathon prediction.

Q5: Does this account for course difficulty?
A: No, the prediction assumes similar course profiles and conditions between your 10K and half marathon races.