Half Marathon Pace Calculator

Find the steady pace you must hold to hit a half-marathon goal time.

How the Math Works

The Half Marathon Pace Calculator uses a straightforward division to determine the required running speed. Since a half marathon is exactly 21.0975 kilometers long, dividing your target total time (in minutes) by this distance yields the pace per kilometer. For example, if aiming for a 2-hour finish (120 minutes), dividing 120 by 21.0975 gives approximately 5.69 minutes per kilometer, which translates to 5 minutes and 41 seconds per km. This calculation assumes consistent pacing throughout the race, ignoring factors like terrain or fatigue.

Practical Applications

To use this calculator practically, first decide on your target half-marathon time based on your fitness level and training. Convert this time into total minutes (e.g., 1 hour 50 minutes becomes 110 minutes). Divide the minutes by 21.0975 to find your required pace per kilometer. Use this pace to structure your training runs, setting interval targets or using a GPS watch to monitor your progress. During the race, check your splits at each kilometer mark to stay on track and avoid starting too fast.

Day-to-Day Use

This calculation transforms abstract race goals into actionable daily plans. By knowing your exact pace requirement, you can schedule training runs that mirror race conditions, building confidence and endurance. It also helps balance life and training by providing a clear framework for time management—whether you’re fitting in a 5K pace workout or simulating a half-marathon's 2-hour effort over multiple sessions. Over time, this clarity reduces anxiety and keeps you focused on incremental progress toward your goal.

Worked example

A 1:45 half → about 4:59 per km (8:01 per mile).

FAQ