Quartile Calculator

Find the quartiles of a data set.

Value 1

Value 2

Value 3

Value 4

Value 5

Value 6

Value 7

Q1 11

Q2 (median) 36

Q3 39.5

IQR 28.5

Formula: Quartiles by linear interpolation

Step-by-step with your numbers:

1. Values used:

2. Value 1 = 6

3. Value 2 = 7

4. Value 3 = 15

5. Value 4 = 36

6. Value 5 = 39

7. Value 6 = 40

8. Value 7 = 41

10. Q1 = 11

11. Q2 (median) = 36

12. Q3 = 39.5

13. IQR = 28.5

Did we solve your problem today?

Quartiles split sorted data into four equal parts.

The math behind it

Q1, Q2 (median) and Q3 sit at the 25th, 50th and 75th percentiles. IQR = Q3 − Q1.

6, 7, 15, 36, 39, 40, 41 → Q1 11, Q2 36, Q3 39.5.

What is the IQR for?

It measures spread and helps flag outliers (beyond 1.5×IQR).