Percentile Calculator

1. Type or paste your numbers, separated by commas, spaces or new lines.
2. Enter the percentile you want, from 0 to 100, such as 25, 50 or 90.
3. Read the percentile value, the count of numbers and the interpolated rank, updating as you type.

Each result means something specific:

A percentile is a value that divides a data set so that a given percentage of the numbers fall at or below it. The 25th percentile is the value a quarter of the data sits below, and the 90th percentile is the value that only the top ten percent exceed. Percentiles turn a raw list into a map of where any value stands.

They are everywhere: exam scores are reported as percentiles, growth charts place a child height in a percentile, and salary surveys quote the 25th, 50th and 75th. The 50th percentile is simply the median, the middle of the data.

It sorts your numbers, finds the position the percentile points to, and interpolates between the two nearest values.

With n sorted values, the rank for percentile p is r = (n - 1) * p / 100. If the rank is a whole number, the answer is that value; otherwise the calculator blends the two neighbouring values in proportion to the fractional part.

1. Sort the numbers from smallest to largest.
2. Compute the rank position from the percentile.
3. Interpolate between the values on either side of that rank.

This linear-interpolation method matches the common spreadsheet percentile function, so results line up with familiar tools.

Take the sorted set 2, 4, 4, 5, 7, 9, 12, 15, 20, 25, which has 10 values. For the 90th percentile the rank is (10 - 1) * 90/100 = 8.1. That points between the values at positions 8 and 9, which are 20 and 25.

Interpolating, the answer is 20 + 0.1 * (25 - 20) = 20.5, so the 90th percentile is 20.5. Ninety percent of the data falls at or below 20.5.

For the 50th percentile the rank is 4.5, between 7 and 9, giving 8, which is exactly the median of the set.

Quartiles and the median are just familiar percentiles, which makes them easy to place.

Because the 50th percentile is the median, the median calculator is a quick way to check a middle value.

The percentile depends on the data and the method, and both matter.

The Data Set

Adding, removing or changing values shifts where each percentile lands, especially in small sets.

The Calculation Method

Several valid percentile definitions exist; this tool uses linear interpolation, which can differ slightly from a nearest-rank method.

Sample Size

Percentiles are more stable in large data sets; in a handful of numbers a single value moves them noticeably.

Ties in the Data

Repeated values are kept and counted, which is correct and can place a percentile exactly on a repeated number.

Test Scores and Grading

See where a score sits relative to a group, or set a cut-off at a chosen percentile.

Growth and Health Charts

Place a height, weight or measurement against reference data reported in percentiles.

Pay and Performance Benchmarks

Compare a figure against the 25th, 50th and 75th percentiles of a survey or data set.

1. Forgetting to Sort

Percentiles are defined on sorted data. This calculator sorts for you, but by hand it is a required first step.

2. Confusing Percentile with Percentage

A percentile is a position in a data set, not a share of a total. The 90th percentile is a value, not 90 percent of something.

3. Expecting One Universal Method

Different tools use different percentile rules, so a small difference from another calculator is normal.

4. Using Too Few Data Points

Percentiles from a handful of numbers are unstable; treat them cautiously.

5. Dropping Repeated Values

Ties count. Include every number, including duplicates, for a correct percentile.

The result is exact for the linear-interpolation method on the numbers you enter, but it is one method among several.

A percentile is the value below which a given percentage of a data set falls. The 90th percentile is the value that 90 percent of the numbers sit at or below.

Sort the data, find the rank with (n - 1) x p / 100, then interpolate between the two nearest values. This calculator does all three steps for you.

Yes. The 50th percentile is exactly the median, the middle value of the data set once it is sorted.

A percentage is a share of a whole, while a percentile is a position in a data set. The 90th percentile is a data value, not 90 percent of a total.

Quartiles are the 25th, 50th and 75th percentiles, splitting the data into four equal parts. The first quartile is the 25th percentile.

There are several valid percentile methods. This tool uses linear interpolation, which can differ slightly from a nearest-rank approach.

Two or more. Percentiles work with any set of two or more values, though they are more stable with larger data sets.

Yes. Include every value, including duplicates, because ties are part of the data and affect where a percentile lands.

No. The calculation runs in your browser, and nothing you enter is sent anywhere unless you Save a result, which stays on this device only.

• Percentile (Wikipedia).
• Percentiles (Maths Is Fun).
• Summarizing quantitative data (Khan Academy).