Class Width Calculator

Calculate optimal class width for creating frequency distributions and histograms

About Class Width

Class width is the difference between the upper and lower boundaries of each class in a frequency distribution.

Formula: Class Width = Range / Number of Classes

Sturges Formula: k = 1 + 3.322 × log₁₀(n)

Tips:

  • Round class width to a convenient number
  • Start the first class at or below the minimum value
  • 5-20 classes typically work best