Free calculator

Quartile calculator

Paste a list of numbers (from Google Sheets, Excel, or plain text) and get Q1, Q2 (median), Q3, IQR, plus min, max, and range. We use inclusive linear interpolation—the same family as QUARTILE.INC / PERCENTILE.INC in Excel. Expand sorted list when n ≤ 24 to review the ordered data. The Google Sheets & Excel block below has copy-ready quartile patterns.

Quartile calculator

Data (one number per line, or separated by spaces, commas, tabs, or semicolons)

Large pastes are parsed after a short pause (200 ms). At most 10000 numbers are used; extra values are ignored for speed.

Results

Count (n): 5
First quartile (Q1): 12
Second quartile (Q2, median): 15
Third quartile (Q3): 18
Interquartile range (IQR): 6
Minimum: 11
Maximum: 22
Range (max − min): 11

Sorted data (same multiset as your input). Quartiles on this page use inclusive positions on the full sorted list—see the methodology for how that compares to some textbook hinge rules.

#	Value
1	11
2	12
3	15
4	18
5	22

Educational and illustrative only. This is not professional statistical advice, survey design, or compensation benchmarking—verify definitions with your course or team when results matter.

When to use this calculator

Quick Q1, Q2, Q3, and IQR for a plain list—before you mirror the same logic in a workbook.

Homework or self-study checks for quartiles and spread between the middle half (IQR).
Line up spreadsheet results with QUARTILE.INC / PERCENTILE.INC on the same pasted range.
See min, max, and range beside quartiles for the same dataset.
Use the mean median mode range tool when you need mode or a different central tendency mix on the same kind of list.

How do you find quartiles from a list?

Start from a numeric list. Sort it smallest to largest. Q1 is the 25th percentile, Q2 the 50th (median), Q3 the 75th, using inclusive linear interpolation between sorted positions—the Excel PERCENTILE.INC / QUARTILE.INC family. IQR is Q3 − Q1.

Sort the data

Quartiles are based on the ordered multiset. Duplicates stay in the list; each occurrence counts toward n.

First quartile (Q1)

Q1 is the value at cumulative proportion 0.25 on the sorted list using inclusive interpolation: position 0.25 × (n − 1) in 0-based index space, with linear blending between neighbors when needed.

Second quartile (Q2)

Q2 is the median: middle value when n is odd, or the average of the two middle values when n is even—the same rule as MEDIAN and QUARTILE.INC(..., 2).

Third quartile (Q3)

Q3 is the 75th percentile with the same inclusive interpolation rule as Q1, at proportion 0.75.

Interquartile range (IQR)

IQR = Q3 − Q1. It describes the span of the middle half of the data for this definition of quartiles.

We do not implement Tukey boxplot hinges, PERCENTILE.EXC, weighted data, or grouped frequency tables—those can change Q1/Q3 for the same numbers.

For mean, median, mode(s), and range without quartiles on the same paste workflow, open the mean median mode range calculator.

For variance and standard deviation with sample vs population control, open the standard deviation calculator.

FAQs on this page cover inclusive vs other definitions, Excel/Sheets names, and salary quartiles (a different workflow).

Google Sheets & Excel

In English function packs, QUARTILE.INC(range, quart) returns inclusive quartiles with quart = 1, 2, or 3 for Q1, Q2, Q3. Equivalent PERCENTILE.INC(range, k) uses k = 0.25, 0.5, 0.75. IQR is QUARTILE.INC(...,3) − QUARTILE.INC(...,1). Replace A1:A99 with your range. If your Excel is not in English, use Formulas → Insert function to match your language pack.

First quartile (Q1)

=QUARTILE.INC(A1:A99,1)

Same 25th percentile rule as this page’s Q1 for an unweighted sorted list.

Second quartile (Q2, median)

=QUARTILE.INC(A1:A99,2)

Matches MEDIAN on the same range for this inclusive definition.

Third quartile (Q3)

=QUARTILE.INC(A1:A99,3)

Same 75th percentile rule as this page’s Q3.

Interquartile range (IQR)

=QUARTILE.INC(A1:A99,3)-QUARTILE.INC(A1:A99,1)

Q3 − Q1 with the same inclusive quartile functions.

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Frequently asked questions

What does this quartile calculator do?

It takes a pasted list of numbers and returns Q1, Q2 (median), Q3, IQR, plus min, max, and range, using inclusive spreadsheet-style percentiles.

What are Q1, Q2, and Q3?

Q1 splits off the lowest 25% of the ordered data at the 25th percentile (under our inclusive rule). Q2 is the median (50th percentile). Q3 sits at the 75th percentile. There is no separate “Q4” in this three-number summary—Q4 wording you may see elsewhere usually refers to calendar fiscal quarters, not these statistics.

What is the interquartile range (IQR)?

IQR = Q3 − Q1. It measures how wide the middle 50% of your ordered data is for the quartile definition we use.

Why might my answer differ from a textbook or another website?

Several different quartile rules exist. This page follows inclusive linear interpolation aligned with Excel QUARTILE.INC / PERCENTILE.INC and Google Sheets inclusive QUARTILE / PERCENTILE. Courses that teach Tukey hinges or exclusive percentiles can get different Q1/Q3 for the same list—especially with small n or duplicates.

Which Excel functions match this page?

Use QUARTILE.INC(range, 1|2|3) or PERCENTILE.INC(range, 0.25|0.5|0.75) on the same sorted multiset. IQR is QUARTILE.INC(range,3) − QUARTILE.INC(range,1).

What are the German Excel names?

Typical Excel (Deutsch) names are QUARTILE.INKL and PERZENTILE.INKL—confirm in Insert function if your build differs.

What are the French Excel names?

Typical Excel (français) names are QUARTILE.INCLURE and CENTILE.INCLURE—verify on your install.

Does Google Sheets match this calculator?

For the inclusive definition, QUARTILE and PERCENTILE in Google Sheets follow the same linear interpolation story as QUARTILE.INC / PERCENTILE.INC in Excel—always spot-check with your exact range.

How do quartiles work for very small lists?

With n = 1, Q1, Q2, and Q3 all equal that value and IQR = 0. With n = 2, quartiles are interpolated between the two numbers under the inclusive rule—still valid for spreadsheets, but compare to your course if the grading rubric uses a different convention.

How are duplicate values handled?

Duplicates stay in the list; sorting keeps every occurrence. n counts all entries, so repeats affect which positions are interpolated.

Is this for salary quartiles or pay bands?

This tool expects a simple numeric list you paste—like homework data or spreadsheet cells. HR “quartiles” or comp benchmarks are a different workflow (weights, job families, samples). Use this page only when your inputs are the actual numbers you want quartiles for.

When should I use the mean–median–mode tool instead?

Open the mean median mode range calculator when you need mode(s), mean, or range without quartiles—or read both tools side by side on the same paste.

Can I enter grouped frequencies or class midpoints?

Not in v1. This page expects raw numbers—one value per parsed token. For grouped distributions, build the expanded list in a sheet first or use coursework tools built for frequency tables.

How should I paste data from a spreadsheet?

Copy a column or row, paste into the box, and keep one number per cell as plain text. Tabs, newlines, spaces, semicolons, and many comma-separated lists work.

Is this professional statistics advice?

No. It is a free educational calculator. For regulated reporting or research protocols, follow qualified experts and your organization’s methods.

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