Free Quartile Calculator

Compute the three quartiles (Q1, Q2, Q3) from five pre-sorted data values.

Q2 (Median)

30.0000

Q1 (25th Percentile)15.0000
Q3 (75th Percentile)45.0000
IQR (Q3 - Q1)30.0000

Q2 (Median) vs Value 1 (Min)

How to Compute Quartiles

Steps (for 5 sorted values)

1. Q2 (Median): The middle value (3rd of 5) 2. Q1: Median of the lower half (values 1 and 2), so Q1 = (v1 + v2) / 2 3. Q3: Median of the upper half (values 4 and 5), so Q3 = (v4 + v5) / 2

Quartiles divide the sorted dataset into four equal parts. Q1 separates the lowest 25%, Q2 is the median, and Q3 separates the lowest 75%.

Example Calculation

Find the quartiles of the sorted dataset: 10, 20, 30, 40, 50.

  1. 01Q2 (Median) = v3 = 30
  2. 02Lower half: 10, 20 → Q1 = (10 + 20) / 2 = 15
  3. 03Upper half: 40, 50 → Q3 = (40 + 50) / 2 = 45
  4. 04IQR = 45 - 15 = 30

Frequently Asked Questions

Learn More

Understanding the Normal Distribution

Learn what the normal distribution is, why it matters in statistics, and how to use the bell curve for probability calculations, z-scores, and real-world data analysis.

Related Calculators