# Quartile Calculator

> Calculate quartiles, the interquartile range, fences, and five-number summary.

Page: https://askcalculators.com/calculator/quartile-calculator/
Definition: https://askcalculators.com/calculator/quartile-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/quartile-calculator/schema.json
Version: 1.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/quartile-calculator/?data=4%2C+7%2C+7%2C+9%2C+12%2C+15%2C+18%2C+21

## Inputs
- data: Data values (comma or space separated); type=text; required; default=4, 7, 7, 9, 12, 15, 18, 21

## Outputs
- q1: First quartile Q1; format=number
- q2: Median Q2; format=number; primary
- q3: Third quartile Q3; format=number
- iqr: Interquartile range; format=number
- lowerFence: Lower outlier fence; format=number
- upperFence: Upper outlier fence; format=number

## Formula
IQR = Q3 − Q1; Tukey fences = Q1 − 1.5IQR and Q3 + 1.5IQR

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.