Excel PERCENTILE Function

What this does

PERCENTILE returns the value at a given position in the distribution. It is how service-level reporting works: a p95 response time says 95 % of requests were faster than this number, which describes user experience far better than a mean. The .INC variant includes the endpoints and accepts k from 0 to 1; the .EXC variant excludes them and rejects k values too close to either end for the sample size. Values between data points are interpolated, so the result often is not a number that appears in the data. Most people learn this as a sequence of clicks and forget it by next week; learning it as a pattern instead is what lets you apply it to the next, slightly different version of the problem without starting from scratch. That is the difference this page is trying to make. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “excel percentile function”. Start on a copy or a tiny sample, keep the affected formula visible, and compare the result with the outcome you expected before you touch the real workbook. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. The point is a calculation you can defend to a CFO or an auditor, but the practical win is that someone else can open the file and understand what happened without asking you.

A worked example

Response times in B2:B5000: =PERCENTILE.INC(B2:B5000, 0.95) gives the p95 latency, and =PERCENTILE.INC(B2:B5000, 0.5) reproduces the median. Setting a compensation band from the 25th to the 75th percentile: =PERCENTILE.INC(C2:C200, 0.25) and =PERCENTILE.INC(C2:C200, 0.75). PERCENTILE is the right summary for response times, salaries and any distribution where the tail is the story, which is exactly where an average misleads. Check the referenced cells, argument order and result type in your workbook. Start with the worked example before changing an input, then compare the changed result with the calculation you expected. An error value or a result of a different type is a reason to inspect the inputs and arguments.

In Google Sheets

Google Sheets support for this task has not been verified. Check the function, arguments and workflow in the target product before transferring the example. Matching formula notation does not establish identical behaviour. The aim was to get you unstuck fast and leave you a little more capable than a copy-paste would. The answer is at the top and the detail above shows why it holds — so the next time a colleague asks, you can answer without reaching for search. For “excel percentile function”, keep the input cells and the result visible while you check the formula in Excel. Follow the worked example and change one input at a time. The steps explain the workbook calculation; this page does not run a live calculator for that task.

Common mistakes

• Passing 90 instead of 0.9, which returns #NUM! because k must be between 0 and 1.
• Using .EXC on a small sample where the requested percentile is not defined, which errors.
• Expecting the result to be an actual data point; percentiles are interpolated between neighbouring values.

Frequently asked questions