PERCENTRANK.INC in Excel: Inclusive Percentile Ranks and Interpolation

• Introduced: the Microsoft function catalogue marks PERCENTRANK.INC as an Excel 2010 addition; an exact first build or preview date is not established here.
• Availability: official help lists Excel for Microsoft 365, Excel for Microsoft 365 for Mac, Excel 2024, Excel 2024 for Mac, Excel 2021, Excel 2021 for Mac, Excel 2019, Excel 2016.
• Checked: October 14, 2026; official PERCENTRANK.INC reference. Documentation and independently modeled examples; no native Excel execution or broader platform certification.

=PERCENTRANK.INC(array, x, [significance])

The dataset and target value are required. The optional significance controls the returned precision; Microsoft describes its default as three digits, 0.xxx. Changing the cell’s display format does not change this argument or recover precision already omitted from a result.

The examples use distinct, increasing numeric observations. For an observed value at one-based position i among n such values, the inclusive fraction is (i-1)/(n-1). Microsoft documents interpolation when the target falls between observed values. Duplicate-rank conventions are deliberately outside this distinct-value audit model.

Enter 10, 20, 40, 80 and 160 in A2:A6. Put this in B2 and fill down:

=PERCENTRANK.INC($A$2:$A$6,A2)

Expected fractions are 0, 0.25, 0.5, 0.75 and 1. Formatted as percentages, they read 0%, 25%, 50%, 75% and 100%. The maximum receives 100% under this inclusive convention.

These are relative positions within this chosen five-record comparison group. A 75% rank does not mean that the measurement itself is 75% of the maximum: 80/160 is only 50%.

=PERCENTRANK.INC(A2:A6,30)

Expected result: 0.375, or 37.5%. The target 30 lies halfway between 20 and 40, whose ranks are 0.25 and 0.5. The interpolated fraction is 0.25+0.5*(0.5-0.25)=0.375.

The output is not the count of records below 30 divided by five. That different calculation is 2/5=0.4. Choose the function that implements the intended reporting definition.

For this strictly increasing dataset, PERCENTILE.INC at probability 0.375 returns 30. Using that value in PERCENTRANK.INC returns 0.375.

=PERCENTILE.INC(A2:A6,0.375)
=PERCENTRANK.INC(A2:A6,30,6)

The first output is in measurement units; the second is a fraction. Here the result terminates exactly at three decimal places, so the default precision already represents it. This example does not prove exact inverse behavior for ties, all sample sizes or fractions shortened by the significance setting.

Keep the original A2:A6 unchanged. In C2:C7 enter 10, 20, 40, 80, 160 and 320.

=PERCENTRANK.INC(C2:C7,80)

Expected fraction: 0.6, compared with 0.75 in the original group. The observed value 80 did not change; its relative position did. When filling a report down, lock the intended comparison range rather than accidentally creating a changing benchmark.

An ordinal RANK.AVG result answers a different question and uses its own handling of ties. Do not relabel an ordinary rank as a percentile without defining a conversion.

Microsoft documents #NUM! for an empty dataset or significance<1. The page does not establish a complete error matrix for out-of-range targets, singleton groups, noninteger significance or mixed error values; those are held rather than inferred from another spreadsheet.

The published examples include shortened fractional results, so do not treat default output precision as a rounding-free mathematical inverse. Inspect the significance argument and the cell format separately. Compare with PERCENTRANK.EXC when an exclusive plotting-position convention is required.

• Microsoft PERCENTRANK.INC reference.
• Editorial testing standards.

Expected results are independent statistical/arithmetic models or explicitly documented rules, not captured native output. Examples use English function names and comma separators. Datasets and reporting policies are fictional.