BYTETOOLS

Percentile Calculator

Find the value at any percentile of a data set using nearest-rank and linear-interpolation methods, or find what percentile a given value falls at.

Paste a data set to find percentiles or percentile ranks.

What is the Percentile Calculator?

The ByteTools Percentile Calculator finds the value at any percentile of a data set — the 25th, 90th, 99th or anything in between.

  • Three methods: nearest rank, inclusive and exclusive interpolation
  • Reverse mode: percentile rank of any value
  • Matches Excel's PERCENTILE.INC and PERCENTILE.EXC results
  • Shows the sorted data so ranks are easy to verify
  • Handles any list size with duplicates and decimals
  • 100% private — data never leaves your browser

How to use the Percentile Calculator

  1. 1

    Paste your data set, separated by commas, spaces or new lines.

  2. 2

    Enter the percentile you want (0–100), e.g. 90 for the 90th percentile.

  3. 3

    Compare the nearest-rank and interpolated results side by side.

  4. 4

    Switch to reverse mode to find the percentile rank of a specific value.

  5. 5

    Copy the summary when you are done.

About the Percentile Calculator

The ByteTools Percentile Calculator finds the value at any percentile of a data set — the 25th, 90th, 99th or anything in between. Because statisticians define percentiles in more than one way, it shows three common methods side by side: nearest rank, linear interpolation inclusive (the Excel PERCENTILE.INC approach) and linear interpolation exclusive (PERCENTILE.EXC).

It also works in reverse: enter a value and it reports the percentile rank, the percentage of data points that fall below it. That makes it useful for interpreting test scores, growth measurements, response times, salaries and any ranked data.

All calculations happen 100% locally in your browser — the data you paste is never uploaded or stored. Results update instantly as you type, and the sorted data set is displayed so you can verify the ranks yourself.

Frequently asked questions

How do you calculate a percentile?

Sort the data, then locate the rank corresponding to your percentile. The nearest-rank method takes the value at rank ⌈p/100 × n⌉, while interpolation methods compute a fractional rank and blend the two neighbouring values. Different textbooks and software use different conventions, which is why this tool shows them together.

Why do Excel and my textbook give different percentile answers?

They use different formulas. Excel's PERCENTILE.INC computes the rank as 1 + p(n−1), the exclusive version uses p(n+1), and many textbooks use the simple nearest-rank rule. All are legitimate; they converge as the data set grows. This calculator labels each result with its method.

What does the 90th percentile mean?

It is the value below which about 90% of the observations fall. If your response time is at the 90th percentile, it is higher than roughly nine out of ten measurements. It does not mean 90% of the maximum value.

What is percentile rank?

Percentile rank flips the question: given a value, what percentage of the data lies below it? This tool counts strictly lower values plus half of the equal values, a common convention that handles ties gracefully.

Is the 50th percentile the same as the median?

Yes, conceptually — the 50th percentile is the median. Depending on the method and whether n is even or odd, interpolated methods return exactly the conventional median, while nearest rank may pick one of the two central values.

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