Race pace calculator
How to use
This calculator lets you calculate the pace necessary to run a certain time in a race, or alternatively, what your finish time will be if you maintain a given pace.
All common track, cross-country, and road racing distances are supported, and you can also calculate paces for custom race distances. Likewise, you can calculate paces per mile, per kilometer, per 400m, per 200m, or for a custom split distance.
Swapping race time and pace time
To flip between "race-to-pace" and "pace-to-race" mode, use the button. In race-to-pace mode (the default), you can enter your goal race time and desired race distance, and the calculator will show you the pace required to achieve your goal race time.
In pace-to-race mode, you can specify your goal pace (/mi, /km, /400m, /200m, or a custom split distance) and the calculator will show you the resulting race time.
When you flip between modes with the button, your calculated race pace will become your entered pace, and vice versa for your calculated race time. So, it's easy to swap back and forth to see the effects of different paces or different goal times.
There might be some small changes in the calculated time or pace when you swap between modes because paces and times are rounded to the nearest second or tenth of a second (depending on whether decimal display, , is enabled).
Adding hours to a race
Some race distances, like 8k, 10k, and 12k, may or may not need an hours digit based on how fast you run (e.g. 1:02:00 for 15k, versus 58:00). For these intermediate race distances, there is a button displayed. Clicking on this button will enable an hours digit.
Custom race and pace distances
You can enter any custom race distance or custom pace distance. This feature is useful when you are preparing for an unconventional race distance (e.g. a 2.9 mile cross country race) or when you do workouts on a loop with an arbitrary distance—for example, the 322-meter indoor track at the University of Notre Dame.
Custom race distances and custom split distances can be entered using meters, yards, kilometers, or miles.
Your custom race distance and custom split distance will stay in memory, even if you temporarily switch to a different race distance or a different split setting.
If you use this calculator on the same device (e.g. your smartphone), your custom race and pace distances will be set as the default the next time you come back.
Decimal settings
You can display (or enter) your race time or your pace with a decimal, if desired. Activate decimal entry using the button next to the race time or pace time entry. Decimal mode is activated by default when you use /400m or /200m splits, and for race distances of one mile and below.
Note that paces and race times may change slightly when you activate or deactivate decimal entry; when the button is disabled, the calculator assumes you intend to set the decimals to zero.
Pace calculator settings
This calculator will remember your settings, including your custom distances, in your browser's local storage. So, when you come back to the calculator later, you'll be able to pick up where you left off. You can reset all settings to their defaults using the button.
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