⏱️ Magic Mile Calculator
Run a hard one-mile time trial (your ‘Magic Mile’), then use it to predict your pace and finish time for common race distances.
What is a Magic Mile?
The Magic Mile is a well-known run-training concept (popularized by veteran running coach Jeff Galloway) in which you run one mile as fast as you comfortably can — not an all-out sprint, but a strong, honest effort — after a short warm-up. That single time becomes a simple, repeatable way to gauge current fitness and predict realistic race paces.
How the prediction works
From your Magic Mile time, this calculator adds a standard adjustment for each longer distance, since race pace naturally slows as distance increases: about 33 seconds per mile slower for a 5K, 40 seconds for a 10K, 50 seconds for a half marathon, and roughly 30% slower per mile for a full marathon.
These are estimates based on a widely used pacing method, not a guarantee — actual race day performance also depends on training, terrain, weather, and pacing strategy. Re-test your Magic Mile every few weeks to track how your predicted paces change as your fitness improves.