Find the value at any percentile of a dataset, with Excel-compatible linear interpolation between ranks.
Your data set — sorted automatically. Example: 10, 20, 30, 40, 50.
Desired percentile (0–100). 50th = median, 75th = third quartile.
Percentile Value
40.0000
Value below which the requested percent of sorted data falls.
Interpolated Rank
4.0000
Position of that value in the sorted list (1-indexed); fractional means interpolated.
Method
Linear interpolation at index (p/100)·(n−1) — Excel PERCENTILE.INC / NIST convention
Interpolation rule used (compatible with Excel PERCENTILE.INC).
What this means
Locates a quantile by sorting and linearly interpolating between neighboring observations when needed.
A percentile is the value below which a given percentage of a data set falls. This tool sorts your data and applies linear interpolation when the percentile falls between two observations.
Formula
index = (p ÷ 100) × (n − 1); value = x⌊index⌋ + (index − ⌊index⌋)·(x⌈index⌉ − x⌊index⌋)
Worked examples
FAQ
How is the 50th percentile different from the median?
With this interpolation convention they are identical: the value at the halfway index.
What does the interpolated rank mean?
It locates the answer within the sorted list, counting from 1. Non-integer ranks indicate the value was interpolated between two observations.