A histogram is a graphical representation of the distribution of numerical data. It groups data into intervals (called bins) and uses bars to show the frequency (count) of data points within each bin. It helps visualize the shape, spread, and central tendency of your dataset.

Bins (or intervals) divide the entire range of data values into consecutive, non-overlapping segments. The width of each bin can be uniform or variable. Our tool creates equal-width bins by default unless you supply custom boundaries. Each bar represents one bin, and its height corresponds to the number of data points falling into that interval.

You have three options: Auto uses Sturges' rule to suggest a bin count based on your data size. Custom Number lets you set any integer between 2 and 100. Custom Bin Boundaries allows you to define exact edges (e.g., 0,10,20,30). The best choice depends on your data distribution and the level of detail you need. Too few bins oversimplify; too many create noise.

Sturges' rule is a classic formula for estimating the optimal number of bins: k = ⌈log₂(n) + 1⌉, where n is the number of data points. It assumes the data is approximately normally distributed and works well for many common datasets. Other methods like Freedman-Diaconis exist, but Sturges is a simple and widely used starting point.

Yes! After generating a histogram, click the PNG button to save the chart as an image. You can also export the frequency table by clicking CSV to download a comma-separated file that opens in Excel, Google Sheets, or any spreadsheet application.

Enter your data as a list of numbers. Accepted delimiters include commas, spaces, tabs, or newlines. Examples: 5, 10, 15 or 5 10 15 or one number per line. Both positive and negative decimals are handled (e.g., -2.5, 3.14). The tool will automatically parse and validate the values.

Relative frequency is the proportion of data points that fall into a given bin. It is calculated as (bin frequency) / (total count). It helps compare distributions across datasets with different total sizes. In the table, it is displayed as a percentage.

If the tool cannot parse your input, it will show an error message. Make sure you only include numbers and valid separators. Remove any text or special characters that are not part of a number. For custom boundaries, provide at least two numeric edges in ascending order.