Our Mission
Running Pace Calculator was created to provide runners of all levels with free, accurate, and easy-to-use tools for training and racing. Whether you're preparing for your first 5K or chasing a Boston Marathon qualifying time, we're here to help you calculate paces, predict race times, and plan your training.
Why We Built This
As runners ourselves, we noticed that most pace calculators online were either:
- Cluttered with ads and difficult to use
- Missing important features like splits and pace adjustments
- Not mobile-friendly for race day use
- Lacking scientific backing for their formulas
We set out to create something better: a clean, comprehensive, and scientifically accurate set of tools that runners actually want to use.
How Our Calculators Work
Pace Calculations
Our pace calculations use straightforward mathematics:
- Pace = Total Time ÷ Distance
- All conversions between kilometers and miles use the exact conversion factor: 1 mile = 1.609344 kilometers
- We round results to the nearest second for practical use
Race Time Predictions
We use two scientifically validated methods:
- Riegel's Formula: T2 = T1 × (D2/D1)^1.06 — widely used and validated across thousands of race results
- VO2max Estimation: Based on the Daniels/Gilbert formula, which estimates maximal oxygen uptake from race performance and predicts performance at other distances
📚 Scientific References:
- Riegel, P. S. (1981). Athletic records and human endurance. American Scientist, 69(3), 285-290.
- Daniels, J., & Gilbert, J. (1979). Oxygen Power: Performance Tables for Distance Runners.
- Jack Daniels' Running Formula (3rd Edition) - VDOT training paces
Training Zones
Our training zones are based on Jack Daniels' VDOT system, the gold standard used by coaches worldwide. We calculate your VDOT from your recent race performance and use it to prescribe optimal training paces for:
- Easy/Recovery runs
- Marathon pace runs
- Threshold/Tempo runs
- Interval training (VO2max)
- Repetition training (speed work)
Pace Adjustments
Our environmental adjustments are based on exercise physiology research:
- Temperature: Based on studies showing 2-3% performance decline per 5°F above 60°F
- Terrain: Research indicates 10-15 sec/km pace reduction per 1% gradient
- Wind: Aerodynamic drag calculations showing 5-20 sec/km impact depending on wind speed
What Makes Us Different
- 100% Free: No premium features, no paywalls, no signup required
- Mobile-Optimized: Works perfectly on your phone during races
- Scientifically Accurate: Formulas based on peer-reviewed research
- Comprehensive: All the tools you need in one place
- Privacy-Focused: We don't store your data or track you
- Ad-Supported: Free to use, supported by non-intrusive ads
Who We Are
We're a small team of runners and developers who believe that great training tools should be accessible to everyone. Our team includes:
- Recreational runners (marathoners and 5K specialists)
- Software developers with a passion for helping the running community
Our Commitment to You
- Accuracy: We regularly review and update our formulas
- Transparency: We explain how our calculations work
- Continuous Improvement: We add features based on user feedback
- Privacy: Your data stays on your device — we don't collect or store it
Get in Touch
Have feedback, suggestions, or found a bug? We'd love to hear from you!
Contact Us →