# Race Corral Calculator

- Link: https://overlandtiming.com/resources/race-corral-calculator/
- Published: 2020-06-21T10:11:14-04:00
- Author: Andrew

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Race director tool

# Race corral calculator

Estimate the size and number of start corrals for your race from your staging area,
the spacing between participants, and your field size.

[Jump to the calculator](https://overlandtiming.com/resources/race-corral-calculator/#calculator)
[How it works](https://overlandtiming.com/resources/race-corral-calculator/#how-it-works)

Overview

## Why corrals, and how many?

Race corrals are often used by large events, or events with a limited staging area,
to group runners of similar abilities and to control how quickly runners flow across
the start and finish lines.

It used to be that the size and number of corrals came from some simple math and
nice even numbers, like groups of 10, 20, or 50, and no one gave a second thought
to how densely runners packed the staging area. When COVID-19 social-distancing 
guidelines arrived in 2020, race directors and timers suddenly needed corrals that
kept runners apart, and the math stopped being simple. We built this calculator 
for that.

It works for any spacing you choose. Setting up the corrals and assigning participants
is easy in [RunSignup](https://help.runsignup.com/support/solutions/articles/17000073677-enable-corrals)
and its RaceDay Scoring suite for timers; this tool helps you decide what to set
up. Questions, feedback, or found a mistake? [Contact us](https://overlandtiming.com/contact/).

![Illustration of runners spaced on a hexagonal grid in a start corral, facing a
red start line](https://overlandtiming.com/wp-content/uploads/2020/06/Asset-17-1024x368.
png)

Calculator

## Size your corrals

Use the sliders to set your staging area width and length, the participant separation,
and the number of participants. The results update as you go: the first set is for
a rectangular grid, the second for a hexagonal grid.

Corral Size Calculator

### Calculation Inputs

---

Distance Unit

   Imperial

   Metric

### Staging area constraints

 Starting Line Width *

15feet

3feet100feet

 Starting Line Width *

4meters

1meters30meters

 Staging Area Length *

50feet

3feet300feet

 Staging Area Length *

15meters

1meters100meters

### Participant constraints

 Participant separation *

6feet

2feet15feet

Note: Use 6 feet to apply the CDC recommended COVID-19 social distancing guidelines

 Participant separation *

1meters

0.5meters5meters

Note: Use 1 meter to apply the WHO recommended COVID-19 social distancing guidelines

 Total number of race participants

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)

 Number of lines of participants

 Number of participants per line

 Number of participants per corral

 Number of corrals

#### Rectangular Grid Arrangement

⌊Rectangular grid⌉⌊Rectangular grid⌉
 _Note: Shown only for illustrative purposes
and does not necessarily match the calculated parameters_

### Corral Size (Hexagonal Grid)

 Number of lines of participants

 Number of participants per line 1, 3, 5...

 Number of participants per line 2, 4, 6...

 Number of participants per corral

 Number of corrals

#### Hexagonal Grid Arrangement

⌊Hexagonal grid⌉⌊Hexagonal grid⌉
 _Note: Shown only for illustrative purposes and
does not necessarily match the calculated parameters_

#### Hexagonal Grid Arrangement

⌊Hexagonal grid⌉⌊Hexagonal grid⌉
 _Note: Shown only for illustrative purposes and
does not necessarily match the calculated parameters_

  If you are human, leave this field blank.

Δ

Calculation deep dive

## How the calculator thinks about your start

The **staging area** (the starting corral area or start chute) is the space where
runners gather in front of the starting line. The diagram shows a simple staging
area defined by its **length** and **width**.

In practice, the width of your staging area is set by the width of your starting
line mats or arch. Check whether your arch is narrower than your mats, or the other
way around. Consider adding a buffer too, so participants aren’t lined up right 
along the edges, crossing the ends of the mats, or running into the arch uprights.
The length is usually more flexible.

A true 6-foot buffer between participants also has to account for the “diameter”
of our bodies. One way to handle that: assume each runner fits in a 1-foot-wide 
circle and set the participant separation slider to 7 feet instead of 6.

![Diagram of a rectangular corral staging area with its length along the course 
and its width along the start line](https://overlandtiming.com/wp-content/uploads/
2020/06/Asset-16-1024x505.png)

### Rectangular or hexagonal grid?

The calculator gives two sets of results: one for arranging participants on a rectangular
grid, one for a hexagonal grid. Does it matter which you use? In practice, probably
not, except in a few unlikely edge cases. I provide both to scratch my own itch 
to go overboard with the analysis.

It’s true that the densest way to pack equal circles on an infinite plane is a hexagonal
grid (a lattice, in nerdspeak), but that’s not what we’re dealing with in race timing.
For most starts, the only rigid constraint is the starting line width. The length
of the staging area usually has some wiggle room, so you can fit as many participants
per corral on a rectangular grid as on a hexagonal one by adding a few more lines.

### When the grid might matter

If you’re timing an indoor event, you may be confined in both directions, and the
arrangement could matter. Two more (unrealistic) cases:

 * You’re a flat-earther holding a race at the edge of the Earth, with your staging
   area flush against the edge: use the hexagonal arrangement for the best density.
 * Your staging area is really, really long and you have thousands of participants.
   For about every 4 lines on a rectangular grid you can fit 5 lines on a hexagonal
   grid, and over a long distance that adds up.

Ultimately, our goal as race timers and race directors is to arrange oblong human
beings in a confined space in a way that balances our love of competition with safety
and consideration for each other. Use this tool, and what you know about your staging
area, to get a reasonable limit on how many people you can accommodate. Marking 
a real grid with small dome cones or chalk paint is probably a good idea; which 
grid you choose is up to you.

Planning your start?

## Talk corrals and timing with us.

We can help you plan your start line, corrals, and timing for race day.

[Contact us](https://overlandtiming.com/contact/)[More resources](https://overlandtiming.com/resources/)
