Percentile Calculator
Enter your data set below to find a value's percentile rank, or find the value at any percentile.
What Is a Percentile?
A percentile splits a data set into 100 equal-sized groups by rank. The nth percentile is the value below which n% of the data falls. Percentiles show up constantly in test scores, growth charts, and income distributions.
Worked example
Data set: 12, 18, 21, 24, 27, 30, 33, 40, 45, 50 (n = 10)
To find the value at the 75th percentile: rank = 0.75 × (10 − 1) = 6.75, which falls between the 7th value (33) and 8th value (40).
Interpolating: 33 + 0.75 × (40 − 33) = 33 + 5.25 = 38.25
Frequently Asked Questions
What does a percentile mean?
A percentile tells you where a value stands relative to the rest of a data set. Scoring in the 90th percentile on a test means you scored higher than about 90% of everyone else who took it.
What's the difference between percentile and percentage?
A percentage describes a proportion of a whole (getting 90% of questions right). A percentile describes a rank relative to other values in a data set (scoring better than 90% of other test-takers) — a 90% score and a 90th-percentile score are usually two very different things.
How is the value at a percentile calculated?
This calculator uses linear interpolation between the closest ranks in the sorted data set — the same method used by Excel's PERCENTILE.INC function — rather than rounding to the nearest existing data point.
What is the median in terms of percentile?
The median is exactly the 50th percentile — the point where half the data falls below and half falls above.
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