The Chicago Marathon Pace Calculator offers runners a tailored race plan. It adjusts splits based on wind, temperature, and course conditions. Input your goal time, start wave, and race-day forecast. The tool uses data from thousands of finishers to create a mile-by-mile plan.

The calculator considers the unique challenges of the Chicago course. These include five river crossings, over 35 turns, and varying wind conditions. It adjusts your pace for each mile, factoring in the wind's effect on your time. This ensures you maintain your goal pace despite environmental changes. Read more culture coverage.

A key feature is the adjustment for GPS inaccuracies in the Loop. The calculator advises runners to use official mile markers for laps. This ensures accurate tracking, especially in areas where GPS watches may drift. This feature helps runners stay on pace and achieve their target finish time. Related: Chicago Marathon Course Features Flat Terrain and Multiple River Crossings.

This original Runner World brief is based on reporting from Marathon Handbook. Visit the source for its complete reporting, context and any later corrections.