Statistics Spread

Measures of Spread Calculator

Compute range, IQR, variance, and standard deviation step-by-step. Toggle between population (÷n) and sample (÷n−1) formulas.

Live · Step-by-Step · Box Plot

Data Input

Data set

Separate values with commas or spaces.

Population or Sample?

Examples

Results

Enter numbers and press Calculate to see spread measures.

Range

—

max − min

IQR

—

Q3 − Q1

Variance

—

σ²

Std Dev

—

Min

—

Max

—

Step-by-Step Work

Box Plot

IQR box Median Whiskers Outliers

Spread Formulas

Range = max − min IQR = Q3 − Q1 Variance σ² = Σ(xᵢ−x̄)² / n (population) Variance s² = Σ(xᵢ−x̄)² / (n−1) (sample) SD = √Variance

Use sample (÷n−1) when your data is a sample from a larger population — this gives an unbiased estimate of population variance.

Step-by-step tutoring makes variance and standard deviation click.