Enter the total number of observations and the percentile rank desired into the calculator to determine the running percentile. This calculator can also evaluate any of the variables given the others are known.

Running Percentile Formula

The following formula is used to calculate the running percentile.

RP = (n + 1) * P / 100


  • RP is the running percentile n is the total number of observations P is the percentile rank desired (decimal)

To calculate the running percentile, add 1 to the total number of observations, then multiply the result by the desired percentile rank. Divide the result by 100. The result is the rank of the observation that falls at the desired percentile.

What is a Running Percentile?

A running percentile is a statistical measure that calculates the percentile of a set of data at a specific point in time in a continuous stream of data. It is often used in time series analysis to understand the distribution of data points and identify trends or anomalies. The running percentile is updated each time a new data point is added to the series, providing a dynamic view of the data’s behavior over time.

How to Calculate Running Percentile?

The following steps outline how to calculate the Running Percentile.

  1. First, determine the total number of observations (n).
  2. Next, determine the desired percentile rank (P) as a decimal.
  3. Next, gather the formula from above = RP = (n + 1) * P / 100.
  4. Finally, calculate the Running Percentile.
  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.

Total number of observations (n) = 50

Desired percentile rank (P) = 75%