About Running Calcs

Running Calcs is a growing collection of simple, focused calculators built to help runners train smarter and make better decisions. Whether you're preparing for a 5K, half marathon, marathon, or ultramarathon, the goal is to provide quick and reliable answers to common running questions.

The site covers the essentials most runners need day to day: pace and finish-time planning, race time prediction, distance conversion, and training tools such as heart rate zones and VO2 max estimation.

Every calculator is designed to be fast, accurate, and easy to share. Enter your values, copy the result, or send a link with your inputs already filled in — useful when comparing paces with a coach or training group.

Running Calcs is still being built out. Additional calculators, training tools, and performance analysis features are planned over time, including deeper race modelling for marathons and ultras.

Running Calcs is an independent project built by a runner, for runners. If you find the calculators useful, please consider sharing them with training partners, running clubs, or anyone else who might benefit.