Enter the peak hour factor and the peak 15 minute flow into the Peak Hour Volume Calculator. The calculator will evaluate the Peak Hour Volume. 

Peak Hour Volume Formula

The following two example problems outline the steps and information needed to calculate the Peak Hour Volume.

PHV = PHR * 4 * P15


  • PHV is the Peak Hour Volume (units/hr)
  • PHR is the peak hour factor 
  • P15 is the peak 15 minute flow 

To calculate the peak hour volume, multiply the peak hour factor by 4, then multiply again by the peak 15 minute flow.

How to Calculate Peak Hour Volume?

The following steps outline how to calculate the Peak Hour Volume.

  1. First, determine the peak hour factor. 
  2. Next, determine the peak 15 minute flow. 
  3. Next, gather the formula from above = PHV = PHR * 4 * P15.
  4. Finally, calculate the Peak Hour Volume.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

peak hour factor = .75

peak 15 minute flow = 15

PHV = PHR * 4 * P15 = ?