Percentile Calculator

About Percentile Calculator

A percentile indicates the value below which a percentage of data falls. The 50th percentile is the median.

How to use this calculator

1. Enter the full dataset of numbers.
2. Choose the value whose percentile rank you want to find.
3. Count how many data values are below that value.
4. Use the formula to convert that count into a percentile.

The formula explained

The formula computes the percentile rank by dividing the number of values below the target value by the total number of data points, then multiplying by 100. It tells you the percentage of the dataset that falls below the chosen value.

• values below = the number of data points that are less than the chosen value
• n = the total number of data points in the dataset

Step by step method

1. List the data and identify the target value.
2. Count how many values are below the target value.
3. Divide that count by the total number of values, then multiply by 100.
4. Interpret the result as the percentile rank.

Worked example

Problem. Find the percentile rank of 78 in this dataset: 52, 60, 61, 67, 71, 78, 80, 84, 90, 95.

1. There are 5 values below 78: 52, 60, 61, 67, and 71.
2. The total number of values is 10, so use \(\frac{5}{10} \times 100\).
3. \(\frac{5}{10} \times 100 = 50\).

Tips and common mistakes

• Be careful to count only values below the target, not values equal to it, unless your class or teacher uses a different convention.
• Always check the total number of data points, because using the wrong \(n\) changes the percentile.

Frequently asked questions