Class Width Calculator
Use our class width calculator to calculate class width instantly for a frequency distribution. Includes the class width formula, a class width formula example, and a clear explanation of what is class width in statistics.
What is Class Width?
Class width is the size of each class interval in a frequency distribution. In statistics, it tells you how wide each bin is when you group data into classes for a histogram or frequency table.
If you’re asking what is class width, think of it as the distance covered by a single class interval. Choosing an appropriate class width helps you summarize data without losing important patterns.
This class width calculator statistics page helps you find class width quickly using the standard class width formula.
Class Width Formula
To calculate class width, subtract the minimum from the maximum to get the range, then divide by the number of classes. Many frequency distributions round the result up to a convenient whole number.
Often rounded up to the next whole number for a clean frequency distribution.
So the class width is 8.
This is the standard approach used for a frequency distribution.
How to Calculate Class Width
- 1
Enter the maximum value from your dataset.
- 2
Enter the minimum value from your dataset.
- 3
Enter the number of classes (class intervals) you want.
- 4
The calculator uses (maximum − minimum) ÷ number of classes to find class width.
Frequently Asked Questions
Use class width = (maximum − minimum) ÷ number of classes.
It’s the size of each class interval when grouping data into a frequency distribution or histogram.
class width = (maximum − minimum) ÷ number of classes (often rounded up).
Find the range (max − min), divide by the number of classes, and round up to a convenient value if needed.
Yes—enter max, min, and number of classes and the class width calculator returns the class width.
Rounding up helps create clean class boundaries (like widths of 5, 10, etc.), which makes the frequency distribution easier to read.
You need the maximum value, minimum value, and the number of classes.
Then the range is 0 and the class width is 0. That usually means there’s no variation in the data.