Interquartile Range Calculator
Verified Calculation Engine
The online Interquartile Range Calculator helps you calculate instantly and solve problems related to Statistics Advanced. This tool provides accurate results using standard formulas and step-by-step calculation; you can view the formula with example in the calculator where available. Whether you are a student, teacher, or professional, this calculator simplifies complex calculations and saves time. Enter the required values below and get instant results. Results are shown clearly, with optional step-by-step explanation where applicable. The tool is free to use and works in any modern browser—no download or installation required. Bookmark this page for quick access whenever you need reliable Math Numbers calculations.
Calculates interquartile range (IQR): IQR = Q₃ - Q₁, the range of middle 50% of data. Used to identify outliers.
Interquartile range:
IQR = Q₃ - Q₁
where Q₁ = first quartile, Q₃ = third quartile
IQR contains middle 50% of data
Outliers: values < Q₁ - 1.5×IQR or > Q₃ + 1.5×IQR
IQR measures spread of middle 50% of data
Inputs
Results
Worked Examples
Example 1: Basic
Find IQR for data [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
- data: [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
- iqr: 5
- q1: 3
- q3: 8
- outlierBounds: [-4.5, 15.5]
Example 2: Board Level
Find IQR for data [10, 20, 30, 40, 50, 60, 70, 80, 90, 100]
- data: [ 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 ]
- iqr: 50
- q1: 30
- q3: 80
- outlierBounds: [-45, 155]
About this calculator
Overview
Interquartile Range Calculator evaluates Interquartile Range for the math / statistics-advanced library. Primary input cue: Data [required]: Array of numerical values. Method anchor: Interquartile range: IQR = Q₃ - Q₁ where Q₁ = first quartile, Q₃ = third quartile IQR contains middle 50% of data Outliers: values < Q₁ - 1.5×IQR or > Q₃ + 1.5×.
When to use
Use Interquartile Range Calculator when you already know the inputs and need interquartile range without setting up a spreadsheet.
Inputs explained
- Data [required]: Array of numerical values
Formula / method
Interquartile range: IQR = Q₃ - Q₁ where Q₁ = first quartile, Q₃ = third quartile IQR contains middle 50% of data Outliers: values < Q₁ - 1.5×IQR or > Q₃ + 1.5×IQR. IQR measures spread of middle 50% of data (calculator id: interquartile-range-calculator).
Worked example
Worked values: data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] → iqr = 5, q1 = 3, q3 = 8, outlierBounds = [-4.5, 15.5]
Interpreting results
Read the primary output as interquartile range under the method on this page.
Assumptions
- Units (when shown) must be consistent across inputs for interquartile range. [interquartile-range-calculator]
- Empty required inputs are not silently replaced with zeros for interquartile range.
- Real-number arithmetic is used unless interquartile range explicitly needs integers.
Limitations
- This page does not provide a full textbook proof for every identity related to interquartile range.
- Interquartile Range Calculator cannot invent missing inputs; incomplete forms stop short of a forged interquartile range value.
- Complex/branch cuts and undefined points are not always interactively annotated for interquartile range.
Important note
Educational mathematics tool. Check edge cases and domain restrictions when results look unexpected.
How to Use This Calculator
- Enter the required values in the input fields.
- Click the Calculate button.
- View the computed result instantly.
Formula Used
Interquartile range: IQR = Q₃ - Q₁ where Q₁ = first quartile, Q₃ = third quartile IQR contains middle 50% of data Outliers: values < Q₁ - 1.5×IQR or > Q₃ + 1.5×IQR. IQR measures spread of middle 50% of data (calculator id: interquartile-range-calculator).
Example Calculation
Worked values: data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] → iqr = 5, q1 = 3, q3 = 8, outlierBounds = [-4.5, 15.5]
Frequently Asked Questions
What is Interquartile Range Calculator?
- Interquartile Range Calculator evaluates Interquartile Range for the math / statistics-advanced library. Primary input cue: Data [required]: Array of numerical values. Method anchor: Interquartile range: IQR = Q₃ - Q₁ where Q₁ = first quartile, Q₃ = third quartile IQR contains middle 50% of data Outliers: values < Q₁ - 1.5×IQR or > Q₃ + 1.5×.
How does Interquartile Range Calculator work?
- Interquartile range: IQR = Q₃ - Q₁ where Q₁ = first quartile, Q₃ = third quartile IQR contains middle 50% of data Outliers: values < Q₁ - 1.5×IQR or > Q₃ + 1.5×IQR. IQR measures spread of middle 50% of data (calculator id: interquartile-range-calculator).
Why use this Math Numbers calculator?
- Use Interquartile Range Calculator when you already know the inputs and need interquartile range without setting up a spreadsheet.