Free Tool
Ultra Distance Calculator | Race Prediction
Ultra Distance Calculator - Predicts ultra-marathon times (50K, 100K, 100mi) from marathon time
Built by an engineer who chases finish lines and is obsessed with data. Thomas Prommer — technology executive who has worked with Google, Apple, Nike, Adidas, Netflix and other global brands. Also an Ironman finisher, HYROX Pro Division competitor, and marathon runner. These tools combine engineering rigor with real race experience.
Ultra Distance Calculator
Predicts ultra-marathon times (50K, 100K, 100mi) from marathon time.
Methodology
Predicts ultra-marathon times (50K, 100K, 100mi) from marathon time. Uses fatigue factors: 50K x1.274, 100K x2.77, 100mi x4.85.
FAQ
How does this work?
Predicts ultra-marathon times (50K, 100K, 100mi) from marathon time. Uses fatigue factors: 50K x1.274, 100K x2.77, 100mi x4.85.
How accurate?
Predictions improve with similar race distances and recent performances.
What affects accuracy?
Training, weather, terrain, race day nutrition, and tapering all affect actual performance.
Should I use this for goal setting?
Yes, use as a starting point. Adjust based on training and conditions.
Predictions based on mathematical models. Actual performance varies.