Use this frequency distribution calculator to summarize how often values appear across categories or grouped intervals. Supports both raw and grouped data with histogram, relative frequency, and cumulative frequency outputs.
What is a frequency distribution?
A frequency distribution is a summary of how often each value or range of values occurs in a dataset. It is one of the foundational tools in descriptive statistics because it reveals the shape, spread, and concentration of data in a way that raw lists cannot.
For small datasets with a limited number of distinct values, an ungrouped distribution lists counts for each value directly. For larger datasets or continuous data, grouping values into class intervals produces a clearer picture of distributional shape without getting lost in individual data points.
How the frequency distribution calculator works
The calculator handles both ungrouped and grouped data. Output includes count, relative frequency, and cumulative frequency for each class, alongside a histogram and ogive for visual interpretation.
Relative frequency converts counts to proportions, making comparison across datasets of different sizes straightforward. The cumulative frequency and ogive are particularly useful for percentile estimation: reading the ogive at any point shows what share of the data falls below that value.
Consistency between the table and the chart is the basic quality check. When they diverge, it almost always points to how intervals were set up rather than a calculation error.
How frequency distributions are used in practice
Frequency distributions appear at the exploratory stage of nearly any data analysis. In business analytics, they help identify where customers, sales, or defects concentrate. In research and statistics, they are the first step toward assessing whether a normal distribution is a reasonable assumption, identifying outliers, and choosing appropriate summary statistics for the data at hand.