Percentile Calculator
Find the percentile rank of a value in a data set, or find the value at any percentile — using the same linear interpolation method as Excel's PERCENTILE.INC function.
How to Use This Calculator
- Enter your data set — paste your list of numbers separated by commas, spaces, or new lines
- Enter a value and/or a percentile — find the percentile rank of a specific value, the value at a specific percentile, or both at once
- Click Calculate — see your result instantly, with the exact formula used
Enter Your Data Set
What Do You Want to Find?
📐 What Is a Percentile?
- A percentile tells you how a value compares to the rest of a data set. If you scored in the 85th percentile, you scored at or above roughly 85% of everyone else.
- This calculator works directly with your actual data — no assumption that it follows a normal (bell curve) distribution. If you need percentiles for a normal distribution instead (e.g. from a mean and standard deviation), use the z-score calculator.
- Percentiles are widely used for test scores, growth charts, salary bands, and standardized exam results (SAT, ACT, GRE).
🧮 Formula Reference
rank = (values below + 0.5 × values equal) ÷ N × 100
index = (p ÷ 100) × (N − 1), then interpolate between the two nearest sorted values
Where N is the number of values in your data set. This is the same interpolation method used by Excel, Google Sheets, and most statistics software.
📊 Percentile vs. Percentage vs. Z-Score
- Percentile: Your position relative to a real group of scores — e.g. "90th percentile" means you beat 90% of the group.
- Percentage score: How many points you earned out of the total possible — e.g. "90%" on a test. These two are easily confused but measure different things.
- Z-score: Assumes your data follows a normal distribution and measures distance from the mean in standard deviations, rather than ranking against actual observed values.
Frequently Asked Questions
What does it mean to be in the 90th percentile?
Being in the 90th percentile means your value is at or above roughly 90% of everyone else in the data set — not that you scored 90% of the total possible points. For example, a 90th-percentile SAT score means you outperformed about 90% of test-takers, regardless of the raw score.
How do you calculate a percentile by hand?
Sort your data from smallest to largest, then use linear interpolation: index = (p ÷ 100) × (N − 1), where N is the number of values and p is the percentile you want. If the index lands between two values, interpolate between them. This is the same method Excel's PERCENTILE.INC and Google Sheets use.
What's the difference between a percentile and a percentage?
A percentage tells you what portion of a total you achieved (e.g. 90% correct on a test). A percentile tells you how you rank compared to a group (e.g. 90th percentile means you scored better than 90% of other test-takers). A high percentage doesn't guarantee a high percentile if the test was easy for everyone.
What is the percentile rank formula?
Percentile rank = (number of values below your score + 0.5 × number of values equal to your score) ÷ total number of values × 100. The 0.5 adjustment for tied values gives a fairer estimate when multiple entries share the same score.
Is the 50th percentile the same as the median?
Yes. The 50th percentile is, by definition, the median of the data set — the value that splits the sorted data exactly in half, with 50% of values falling below it and 50% above.
Why do different percentile calculators give slightly different answers?
There are several accepted percentile methods (e.g. Excel's PERCENTILE.INC vs. PERCENTILE.EXC, or the nearest-rank method), which handle interpolation between data points differently. Results are usually very close but can differ by a small amount — especially with small data sets. This calculator uses the linear interpolation method (PERCENTILE.INC), the most common default.