A fast, lightweight tool for runners and coaches.
Running requires quick math. When planning a workout or predicting a race time, you need answers instantly. We built this calculator to be:
The calculator uses the fundamental running formula: pace × distance = total time. Enter any two values, and the third is calculated instantly. Switch between kilometers and miles with one click.
We use the exact SI conversion: 1 mile = 1.609344 kilometers. This is the standard used by all athletic organizations.
The pace bands table shows typical pacing ranges for common running activities. These are guidelines based on running physiology; your actual pace depends on fitness, terrain, and conditions.
All calculations happen in your browser. We don't collect, store, or transmit your data. Read our privacy policy for details.
Built with Astro for maximum performance and minimal overhead.