Percentile Calculator

Calculate percentile values and ranks from your data. Supports multiple calculation methods with step-by-step solutions and percentile tables.

Formula:r = (p/100) x (n+1)

Results

50th Percentile

35.0000

Using exclusive method

Data Count15
Rank Position8.00
Mean36.53
Min12.00
Max65.00

Enter Your Data

15 numbers entered | Range: 12.00 to 65.00

Percentile Settings

Enter a value between 0 and 100

Display 5th, 10th, 25th, 50th, 75th, 90th, 95th, 99th percentiles

Result

50th Percentile Value

35.0000

50% of values are below 35.00

Rank Position

8.00

of 15

Step-by-Step Calculation

Step 1:Data sorted: [12, 15, 18, 22, 25, 28, 30, 35, 40, 45...]
Step 2:n = 15, percentile = 50
Step 3:Rank = (50/100) x (15+1) = 8.0000
Step 4:Rank is integer, value at position 8 = 35

Common Percentiles Table

PercentileValueZ-ScoreMeaning
5th12.00-1.515% below this value
10th13.80-1.4010% below this value
25th (Q1)22.00-0.8925% below this value
50th (Median)35.00-0.0950% below this value
75th (Q3)50.000.8375% below this value
90th62.001.5790% below this value
95th65.001.7595% below this value
99th65.001.7599% below this value

Percentile Rank (Reverse Lookup)

Enter a value to find what percentile it represents in your data.

Enter a value above

Sorted Data

121518222528303540454850556065

Highlighted value is closest to the 50th percentile (35.00)

Calculation Methods

Exclusive (R6)

r = p(n+1)/100

Excel PERCENTILE.EXC, treats data as sample

Inclusive (R7)

r = 1 + p(n-1)/100

Excel PERCENTILE.INC, most common method

Nearest Rank

r = ceil(pn/100)

No interpolation, returns actual data value

Results

50th Percentile

35.0000

Count15
Rank8.00

?How Do You Calculate Percentile?

A percentile indicates the value below which a given percentage of data falls. To find the pth percentile: 1) Sort data in ascending order. 2) Calculate rank r = (p/100) x (n-1) + 1 (or similar formula based on method). 3) If r is a whole number, take that value. 4) If r is between integers, interpolate between adjacent values. The 50th percentile is the median.

What is a Percentile?

A percentile is a measure used in statistics indicating the value below which a given percentage of observations fall. For example, the 90th percentile means 90% of the data is below that value. Percentiles divide a data set into 100 equal parts and are commonly used in standardized testing, growth charts, and data analysis to understand relative standing within a distribution.

Key Facts About Percentiles

  • Percentile shows the percentage of data below a certain value
  • 50th percentile = median (middle value)
  • 25th percentile = Q1 (first quartile)
  • 75th percentile = Q3 (third quartile)
  • Multiple calculation methods exist (exclusive, inclusive, R-style)
  • Formula (exclusive): r = (p/100) x (n+1)
  • Formula (inclusive): r = (p/100) x (n-1) + 1
  • Percentile rank = (values below x / total values) x 100
  • Z-score can be converted to percentile using normal distribution

Quick Answer

A percentile indicates the value below which a given percentage of data falls. To find the pth percentile: 1) Sort data in ascending order. 2) Calculate rank r = (p/100) x (n-1) + 1 (or similar formula based on method). 3) If r is a whole number, take that value. 4) If r is between integers, interpolate between adjacent values. The 50th percentile is the median.

Frequently Asked Questions

A percentile indicates the value below which a given percentage of observations fall. For example, if your test score is at the 90th percentile, you scored higher than 90% of test takers.
Sort your data in ascending order. Calculate the rank using r = (p/100) x (n+1) for exclusive method or r = 1 + (p/100) x (n-1) for inclusive. If r is not a whole number, interpolate between adjacent values.
Percentile rank tells you what percentage of values fall below a specific value. Formula: (count of values below x / total count) x 100. This is the inverse of finding a percentile value.
Exclusive method (R type 6) uses r = p(n+1)/100, treating data as a sample from a larger population. Inclusive method (R type 7) uses r = 1 + p(n-1)/100, treating endpoints as the full range. Results differ slightly.
Common percentiles include: 25th (Q1, first quartile), 50th (median), 75th (Q3, third quartile), 90th, 95th, and 99th. Quartiles divide data into four equal parts; deciles into ten parts.
For normally distributed data, z-scores can be converted to percentiles. z=0 is the 50th percentile (mean), z=1 is about 84th percentile, z=2 is about 98th percentile, z=-1 is about 16th percentile.

Last updated: 2025-01-15