Built by an Engineer, Tested by an Athlete

Training Calculators

Precision tools from a hybrid athlete & engineer. The same algorithms I use for my own marathon, Ironman, and HYROX preparation.

222 Free Calculators
10 Categories
5 Languages
Thomas Prommer - Hybrid Athlete
1:27
Thomas Prommer - Hybrid Athlete
Engineering Performance Thomas Prommer — Hybrid Athlete
English 1:27

The same calculations I use for my own marathon, Ironman, and HYROX preparation. Find a calculator or browse by category below.

Real Algorithms, Real Results

Ported from My Own Training System

These calculators are ported from the training analysis system I built for my own marathon and Ironman preparation. They use the same algorithms used by professional coaches and sports scientists.

15+ Marathons Completed
3 Ironman Finishes
10+ HYROX Events

Done calculating? Start training.

Turn these numbers into an AI-built plan that adapts weekly.

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By the maker of 170+ free training calculators