Tools & resources
Marathon training utilities built by coaches
Plan smarter race efforts, model course difficulty, and share interactive tools with your athletes. Everything here is free to use online or embed in your team site.
Featured
Marathon Pace Calculator
Turn your finish time goals into precise mile and kilometer splits, share pacing charts, and embed the calculator anywhere.
- Race-day pacing
- Split projections
- Embeddable widget
Featured
Race Difficulty Analyzer
Quantify race difficulty using elevation, weather, and course profile to fine-tune pacing plans and crew strategies.
- Course scoring
- Pacing adjustments
- Crew checklist
Roadmap
What we’re building next
Help us prioritize the next generation of MarathonOS tools—Pilot testers get early access and direct input into features.
Fuel Planner
In development
Dial in carb intake and hydration for long efforts with science-backed guidance.
Race Day Checklist
Researching
Build a customizable packing and logistics list for your crew and travel.
Want to contribute an idea? Email the 42Cal team and we’ll add you to our beta roster.