Race Corral Calculator

Use our Race Corral Calculator to estimate the size and number of race corrals for your race event. It’s now particularly relevant for determining race corral sizes subject to COVID-19 social distancing guidelines. Read the Calculator Deep Dive section to learn more or jump to the Calculator Instructions below to get started. Please contact us if you have any questions, feedback, or find a mistake!

Race corrals are often used by large events, or events with a limited staging area, to help partition runners into groups of similar abilities and to control the rate at which runners flow through the start/finish lines. It used to be that the size and number of corrals could be easily determined with some simple math and nice even numbers like groups of 10, 20, 50, etc. No one ever gave a second thought about the density of runners within the staging area. Packing runners tighter than sardines into a finite staging area has always just been part of the experience.

All that has changed due to COVID-19. For the foreseeable future, race directors and race timers for in-person race events of any size may find themselves needing to implement race corrals to enforce social distancing. It’s super easy to create and configure the corrals and assign participants to them using RunSignup and their awesome RaceDay Scoring Suite for timers. But determining the size and number of corrals to configure in your registration platform or timing software is no longer as easy to calculate with social distancing guidelines applied.

Corral Staging Area Graphic

I’m working on a blog post to detail the nitty-gritty details. Check back soon. For now, note the following:

The “staging area” (aka, the starting corral area, starting line chute, etc.) is the region of space where runners congregate in front of the starting line. The graphic below illustrates a simple corral staging area defined by its length and width.

Corral Staging Area

In practice, the width of your staging area will be constrained by the width of your starting line mats or arch. Take care to consider whether the width of your arch is less than your mats, or vice versa. Also, consider adding a buffer to account for the fact that you probably don’t want participants aligned directly along the edges of your staging area. Otherwise, the participant will be crossing the ends of your starting line mats or running into the uprights of your arch. The length of your staging area will typically be more flexible.

Furthermore, understand that in order to have a true 6-foot buffer between participants would require accounting for the “diameter” of our bodies. You might account for this by giving everyone the benefit of the doubt and assuming your participants could be squeezed into a 1-foot diameter tube and setting the participant separation slider to be 7 feet instead of 6.

I offer two sets of results. The first set of calculations gives you numbers for arranging participants in a rectangular grid. The second set gives you the numbers for a hexagonal grid.

Does it matter which set you use? In practice, probably not, except for a few, unlikely or unrealistic edge cases. I’m merely providing both sets of results to scratch that itch of mine to go overboard with the analysis.

Although it’s true that the optimal density of uniform circles/discs confined to an infinite plane is achieved by arranging them on a hexagonal grid (or lattice, in nerdspeak), that’s not what we’re dealing with in race timing. Furthermore, for most scenarios, the only real or rigid geometric constraint is the starting line width. The length of the staging area will typically be much more flexible and allow some “wiggle room”, allowing you to fit the same number of participants per corral in the staging area using a rectangular grid as you would using a hexagonal grid by simply adding a few more lines of participants. Of course, if you’re timing an indoor event, maybe you are confined in both dimensions, in which case, the arrangement you choose might matter. I can think of two more unrealistic scenarios where it could matter:
  • You’re a flat-earther holding a race at the edge of the Earth. If your staging area is flush with the edge, then you might want to use the hexagonal arrangement for optimal density.
  • Your staging area is really really long and you have thousands of participants. For about every 4 lines of participants arranged on a rectangular grid, you can squeeze in five lines of participants arranged on a hexagonal grid. Over a really long distance, those numbers will certainly add up.

Ultimately, as race timers and race directors, our goal is to arrange oblong human-beings into a confined region of space in a manner that balances our love of competition and sport with the need for safety and consideration for each others well-being. Based on your knowledge of your race’s staging area, you can use this tool to obtain a reasonable limit on the number of people you could reasonably expect to accommodate for your race. Placing a real grid with small dome cones or chalk paint in your staging area is probably a good idea, but which grid you choose is up to you.

Use the sliders below to set your staging area width and length as well as the participant separation and the number of participants. As you change the slider values, the calculation results below will be dynamically updated. I offer two sets of results. The first set of calculations gives you numbers for arranging participants in a rectangular grid. The second set gives you the numbers for a hexagonal grid. Read the Calculation Deep Dive section above for my take on the most suitable grid.

Corral Size Calculator - Imperial + Metric

Calculation Inputs


Distance Unit

Staging area constraints

15feet
3feet100feet
4meters
1meters30meters
50feet
3feet300feet
15meters
1meters100meters

Participant constraints

6feet
2feet15feet
Note: Use 6 feet to apply the CDC recommended COVID-19 social distancing guidelines
1meters
0.5meters5meters
Note: Use 1 meter to apply the WHO recommended COVID-19 social distancing guidelines
250participants
0participants1000participants
Note: Required for calculating the number of corrals from the calculated corral size

Calculation Results

Note: Results are updated dynamically


Corral Size (Rectangular Grid)

Rectangular Grid Arrangement

Rectangular grid
Note: Shown only for illustrative purposes and does not necessarily match the calculated parameters

Corral Size (Hexagonal Grid)

Hexagonal Grid Arrangement

Hexagonal grid
Note: Shown only for illustrative purposes and does not necessarily match the calculated parameters

Hexagonal Grid Arrangement

Hexagonal grid
Note: Shown only for illustrative purposes and does not necessarily match the calculated parameters