Quartile Calculator

Use our free quartile calculator to compute Q1, Q2 (median), Q3, interquartile range (IQR), and outlier detection fences.

Math

Numbers

Formula

Quartiles divide a data set into four equal parts. Q1 is the 25th percentile, Q2 the median (50th), Q3 the 75th. IQR = Q3 - Q1. Values below Q1-1.5×IQR or above Q3+1.5×IQR are potential outliers.

Q1 (25th), Q2 (50th/median), Q3 (75th), IQR = Q3 - Q1

Percentage: The percentage value you want to apply

Number: The original number or value

Result: The calculated result

How It Works

1Enter numbers separated by commas.
2Click Calculate to get all quartiles, IQR, and outlier fences.

Examples

Data: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

1.Q1=27.5, Q2=55, Q3=82.5
2.IQR=55, fences: -55 and 165

Result: 55.0000

Frequently Asked Questions

Values that divide data into four equal parts (25%, 50%, 75%).

Interquartile range = Q3 - Q1, measuring the middle 50% spread.

Values below Q1-1.5×IQR or above Q3+1.5×IQR are outliers.

The median of the lower half of the data (25th percentile).

The median of the upper half of the data (75th percentile).

Related Calculators

Median Calculator Percentile Calculator Standard Deviation Calculator Mean Calculator Percentage Calculator Basic Calculator

CalculateMe Team

Last updated: 2026-07-14

Quartile Calculator

Formula

How It Works

Examples

Data: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

Frequently Asked Questions

What are quartiles?

What is IQR?

How to detect outliers?

What is Q1?

What is Q3?

Related Calculators

Quartile Calculator

Formula

How It Works

Examples

Data: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

Frequently Asked Questions

What are quartiles?

What is IQR?

How to detect outliers?

What is Q1?

What is Q3?

Related Calculators