When frequency histograms help
A frequency histogram works well when the count in each interval matters. Exam score bands, order value ranges, lab measurements, response times, and patient ages are common examples.
Histogram topic
How to Make a Frequency Histogram
Use this guide when you need to see how many values fall into each interval. It works for pasted data, CSV exports, classroom assignments, lab summaries, and business reports.
The main tool includes count, relative frequency, density, cumulative count, and cumulative percentage views. You can also export the full frequency table as CSV.
Worked example
From exam scores to relative frequency
These 50 built-in sample scores are grouped into 6 bins using the tool’s default Freedman–Diaconis rule. Each bar shows the fraction of scores in its interval.
Sample scores
58, 62, 64, 67, 68, 69, 71, 72, 73, 74, 74, 75, 76, 77, 78, 78, 79, 80, 81, 82, 82, 83, 84, 85, 85, 86, 87, 88, 88, 89, 90, 91, 91, 92, 93, 94, 95, 96, 97, 55, 61, 70, 76, 83, 87, 89, 92, 94, 98, 99
50 values · minimum 55.00 · maximum 99.00
Open this example in the tool| Interval | Count | Relative frequency |
|---|---|---|
| [55.00, 62.33) | 4 | 8.0% |
| [62.33, 69.67) | 4 | 8.0% |
| [69.67, 77.00) | 9 | 18.0% |
| [77.00, 84.33) | 11 | 22.0% |
| [84.33, 91.67) | 12 | 24.0% |
| [91.67, 99.00] | 10 | 20.0% |
Each interval includes its left edge and excludes its right edge; the final interval includes both edges. Percentages may be rounded.
For example, 12 of the 50 values fall in [84.33, 91.67). The relative frequency is 12 ÷ 50 ≈ 0.240 (24.0%). Switch the tool’s y-axis to Count to show counts instead.
Export the table behind the chart
After choosing a binning method, download the CSV frequency table to review the exact bin starts, ends, counts, relative frequencies, density values, and cumulative totals.
FAQ
What is a frequency histogram?
A frequency histogram groups numeric data into intervals called bins and draws one bar for each interval. The height of each bar is the count of values in that range. Use it when the count per interval is the main number readers need.
Can I export the frequency table?
Yes. After building the histogram, download a CSV frequency table that includes each bin's start and end, count, relative frequency, density, cumulative count, and cumulative percentage. Use this for supplementary material or for reviewing the exact bin values behind the chart.
Can I use relative frequency instead of count?
Yes. The Y-axis selector offers five options: count, relative frequency, density, cumulative count, and cumulative percentage. Switching the view changes the scale used to display each bar's height. It does not change the bins.
Build a histogram from your data
Paste numbers, upload a CSV or TXT file, choose bins, edit labels and styles, then export SVG, PDF, PNG, CSV, or JSON.
Open the tool