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Need a shortcut to help you perform load testing calculations?

Download a complimentary copy of the Excel calculator referenced in our blog: Solving the CAPS Rate Mystery in Load Testing.

When designing an effective load test, you will need to define three variables:

  • Call Attempts Per Second (CAPS)
  • Average call duration
  • Number of concurrent calls


Apply your values to the formula below to calculate the maximum number of concurrent calls. Changing the value of any one of these three key variables will cause one or both of the others to change.

Call Duration (in minutes or fractions of minutes) x CAPS Rate (whole number) x 60 (convert call duration to seconds) x Dialing success factor (percentage) = Maximum number of concurrent calls.

How to Use this Calculator
You can use the Excel worksheet developed by Cyara’s Principal Solution Architect, Mark Ryan, to quickly enter differing values and see how they will affect the result, enabling you to determine where you may need to make adjustments.

Download and save your copy of the worksheet, then enable editing to adjust the values.

Be sure to read Mark’s full explanation on his blog post, Solving the CAPS Rate Mystery in Load Testing.