Percentile Calculator
Find any percentile of a data set and the percentile rank of a score, with the method explained step by step.
Calculate a percentile and a percentile rank
Your results
Your sorted values and their ranks
Values sorted from smallest to largest, with the percentile rank of each value. The score you entered is highlighted.
How percentiles work
This free calculator finds any percentile of a data set and the percentile rank of a score. It is for students, teachers, researchers and anyone comparing a result with a group. There is no sign-up, and everything runs in your browser, so your numbers never leave your device.
What is a percentile?
A percentile is a value below which a given percentage of the data falls. The 90th percentile is the value below which 90 percent of the numbers sit, so only 10 percent are higher. Percentiles split a sorted data set into hundredths, and they are used for test scores, growth charts, salaries and rankings.
Percentiles are relative, not absolute. A score at the 90th percentile in one class could be at the 60th percentile in a stronger class, because the rank depends on the group you compare against.
How is a percentile calculated?
This calculator uses the linear interpolation method, the same method as the PERCENTILE.INC function in Excel. Sort the data, work out the rank as the percentile divided by 100 times one less than the count, then interpolate between the two nearest values. For 10, 20, 30, 40 and 50, the 90th percentile is 46.
Step by step for that example: the rank is 0.9 times 4, which is 3.6. The value at position 3 is 40 and at position 4 is 50, so the answer is 40 plus 0.6 times 10, which is 46. Positions start at 0 in this method.
What is the difference between a percentile and a percentage?
A percentage is a share of a whole, while a percentile is a position in a sorted list. Scoring 80 percent on a test means you answered 80 percent of the questions correctly. Being in the 80th percentile means you scored better than 80 percent of the people who took the test.
The two are often confused in school results. A student can score 60 percent on a hard paper and still sit at the 90th percentile, if most of the class scored even lower.
What is percentile rank?
Percentile rank tells you what share of the data sits below a given score. This calculator uses the count below plus half the count equal, divided by the total count, times 100. In the set 10, 20, 30, 40 and 50, the score 40 has three values below it and one equal to it, so its rank is 70 percent.
Counting half of the equal values is a fair compromise. If five people share the same score, some of them are effectively below the others, so giving the whole group full credit would overstate the rank.
What does the 90th percentile mean?
Being at the 90th percentile means you scored higher than 90 percent of the group and lower than the top 10 percent. It is a common cut-off for top performers in exams, salaries and health measures. The World Health Organization growth charts, updated in 2006, use percentiles to track whether a child’s height and weight are developing normally.
The table below was worked out with the same formulas this calculator uses, on ten exam scores from 55 to 85.
| Percentile | Rank used | Value | Reading |
|---|---|---|---|
| 25th | 2.25 | 63.5 | Quarter of scores below |
| 50th (median) | 4.5 | 71 | Half of scores below |
| 75th | 6.75 | 77.25 | Three quarters below |
| 90th | 8.1 | 80.5 | Top 10 percent above |
Frequently asked questions
What is the difference between a percentile and a quartile?
Quartiles are just three special percentiles: the 25th, the 50th and the 75th. The 50th percentile is also the median. Percentiles split the data into 100 parts, while quartiles split it into 4 parts.
Can a percentile be more than 100?
No. Percentiles run from 0 to 100, because they describe a share of the data. The 100th percentile is the largest value in the set, and nothing can sit above all of the data.
What is the percentile rank of the highest value?
With this method it is just under 100 percent, because half of the equal values are counted. For a set of 5 values, the highest value has 4 below it and 1 equal, so its rank is 90 percent.
Why do different calculators give different percentile answers?
There are several accepted methods, and they disagree slightly when the rank falls between two values. This calculator uses linear interpolation, the Excel PERCENTILE.INC method, which is the most common choice for school and research work.
What is the percentile rank of the lowest value?
With this method it is above 0 percent, because half of the equal values are counted. For a set of 5 values, the lowest value has 0 below it and 1 equal, so its rank is 10 percent.
How many values do I need?
You need at least one value, but percentiles are more useful with more data. With only 2 or 3 values, most percentiles are just interpolated guesses between the points you have.
Is my data sent anywhere?
No. This calculator runs entirely in your browser. Nothing you paste is uploaded, stored or shared with anyone.
More statistics tools
Working with averages? Try the Mean Median Mode Calculator. Working with chance? Try the Probability Calculator. Comparing two variables? Use the Correlation Coefficient Calculator. For spread in more depth, see the Standard Deviation Calculator, and for standardised scores use the Z-Score Calculator, the P-Value Calculator and the Confidence Interval Calculator.
