Class Width Calculator
Divide the data range by your chosen number of classes to estimate histogram bin width.
Formula
w = (maximum − minimum)/k.
Unrounded class width ≈ (80)÷(8)
How to use
- Enter the minimum and maximum.
- Enter the number of classes.
- Read the width, then choose suitable rounding.
Examples
- Values from −5 to 6 in four classes give width 2.75.
Frequently asked questions
Should I round the width?
Choose a practical width for your data and units; round upward when needed to cover the range.
How do I include the largest value?
Close the last interval at its upper boundary, or adjust the boundaries.
What if all values are equal?
The range and computed width are zero; choose a positive width for plotting.
Sources
Updated: