Lower And Upper Class Widths Calculator

Lower and upper class widths are crucial in statistics to determine the range of a dataset. Our calculator helps you find these values quickly and accurately.

1. Enter the lower and upper class limits.
2. Click ‘Calculate’.
3. View the results and chart.

The lower class width is calculated as Class Size / (Frequency of the class + 1), and the upper class width is Class Size / Frequency of the class.

Dataset	Lower Class Width	Upper Class Width
IQ scores of 100 students	5.0	10.0
Salaries of 200 employees	2.5	5.0

Class Interval	Frequency	Lower Class Width	Upper Class Width
10-20	15	1.33	2.67
20-30	30	0.67	1.33

• Use these values to create a frequency distribution histogram.
• Be mindful of the class size when choosing intervals.

What are class intervals?

Class intervals are ranges of values used to group data for analysis.

Why are class widths important?

Class widths help determine the accuracy of the frequency distribution.

UK Office for National Statistics – US Census Bureau