Histogram Maker
Paste a list of numbers and get a histogram instantly — with automatic bins, a frequency table, and the key statistics of your data. Download the chart as PNG or SVG. Free, no signup, and your data never leaves your browser.
Try an example data set
Renders locally in your browser — your data is never uploaded.
Statistics of your data
Count (n)
40
Mean (x̄)
73.35
Median
73.5
Std. Deviation (s)
10.4208
Minimum
48
Maximum
95
Bin width
10
Bins
6
Need the full step-by-step statistics? Standard Deviation Calculator · Mean, Median, Mode Calculator
Frequency table
| Class interval | Frequency | Relative frequency | Cumulative |
|---|---|---|---|
| [40, 50) | 1 | 2.5% | 2.5% |
| [50, 60) | 3 | 7.5% | 10% |
| [60, 70) | 10 | 25% | 35% |
| [70, 80) | 15 | 37.5% | 72.5% |
| [80, 90) | 8 | 20% | 92.5% |
| [90, 100] | 3 | 7.5% | 100% |
- 01Make a histogram online in seconds — paste data, the chart updates live.
- 02Automatic bins (Sturges' rule) or set your own number of bins.
- 03Switch between frequency counts and relative frequency (%).
- 04See mean, median, standard deviation, and a full frequency table.
- 05Download as PNG or SVG, or share a link that reproduces your chart — free, no signup.
Why Use This Histogram Maker
Instant Live Chart
The histogram redraws as you type — no upload step, no waiting. Paste values straight from Excel, Google Sheets, or a CSV column and the frequency distribution appears immediately.
Smart Automatic Bins
The bin count is chosen with Sturges' rule and bin edges snap to clean, round numbers, so the histogram is readable by default. Prefer full control? Set any number of bins from 1 to 60.
Statistics Included
Every histogram comes with the numbers behind it: count, mean, median, sample standard deviation, minimum, maximum, and bin width — plus a full frequency table with relative and cumulative percentages.
Frequency or Percentage
Switch the y-axis between raw frequency counts and relative frequency in percent — the standard views asked for in statistics classes and reports.
Export and Share
Download a publication-ready chart with one click: a crisp 2× PNG for slides and homework, or a scalable SVG you can edit in any vector tool. Copy the image straight to your clipboard, or share a link that rebuilds the exact chart — data and settings included.
Free and Private
Everything runs in your browser — your data is never uploaded to a server. No signup, no limits, no paywall. Just make a histogram and go.
What Is a Histogram?
A histogram is a chart that shows the frequency distribution of numerical data. The data range is divided into consecutive intervals called bins (or classes), and each bin is drawn as a bar whose height shows how many values fall inside it. Histograms reveal the shape of your data at a glance: where values cluster, how spread out they are, whether the distribution is symmetric or skewed, and whether there are gaps or outliers.
Whether you are checking homework, exploring measurements in a lab, or profiling response times in production, a histogram is usually the first chart to draw — and this free histogram generator gives you the chart and the statistics in one place.
- Histogram vs Bar Chart
- A histogram groups continuous numerical data into intervals, so the bars touch and their order is fixed by the number line. A bar chart compares separate categories, so the bars are drawn with gaps and can be reordered. If your x-axis is a measurement scale, you want a histogram.
- Bins and Bin Width
- Bins are the equal-width intervals the data is grouped into, and the bin width controls the level of detail. Few, wide bins smooth the picture and can hide structure; many narrow bins show detail but look noisy. This tool picks a sensible count automatically and lets you override it.
- Reading the Shape
- A roughly symmetric bell shape suggests normally distributed data. A long tail to the right means positive skew (common with times and incomes), a tail to the left means negative skew, and two separate peaks (bimodal) often mean two different groups are mixed in one data set.
- Frequency vs Relative Frequency
- A frequency histogram shows raw counts per bin; a relative frequency histogram shows each bin as a percentage of all values. Percentages make it easy to compare distributions of data sets with different sizes.
How to Make a Histogram Online
- 01
Paste your data
Type or paste your numbers into the data box, separated by commas, spaces, or new lines. Copying a column straight from Excel or Google Sheets works — decimals and negative values are supported.
- 02
Adjust the bins
The histogram appears instantly with automatic bins. Change the number of bins to zoom the level of detail in or out, and switch the y-axis between counts and percentages.
- 03
Label your chart
Set the chart title and the x- and y-axis labels so the histogram is self-explanatory in a report or assignment. Pick a bar color to match your document.
- 04
Download and interpret
Export the finished histogram as PNG or SVG. Use the statistics strip and the frequency table below the chart to describe the distribution: center, spread, and shape.
Tips for Better Histograms
Try Several Bin Counts
The shape of a histogram can change a lot with the bin width. Always look at your data with a couple of different bin counts before drawing conclusions — real features persist, artifacts disappear.
Start the Y-Axis at Zero
Bar heights encode frequency, so a truncated y-axis exaggerates differences. This tool always draws the frequency axis from zero — keep it that way when you restyle the export.
Use Enough Data
With fewer than about 20 values a histogram is mostly noise — a dot plot or a stem-and-leaf plot tells the story better. Histograms shine from roughly 30 values upward.
Label the Units
An x-axis that says "Score" or "Time (ms)" makes the chart readable on its own. Include the units in the axis label, not just in the title.
Compare with Percentages
When comparing two data sets of different sizes, switch to relative frequency so both histograms are on the same 0–100% scale and shapes can be compared directly.
Check Skew Against Mean and Median
If the mean is clearly larger than the median, expect a right-skewed histogram; if smaller, left-skewed. The statistics strip under the chart lets you verify the shape you see.
Histogram Concepts and Formulas
Definition of a histogram
A histogram is a graphical summary of the distribution of numerical data: the x-axis is divided into equal-width intervals (bins) and each bar's height shows the number — or percentage — of values that fall into that interval.
What a histogram tells you
- Center: where the values concentrate (compare with the mean and median).
- Spread: how wide the distribution is (compare with the standard deviation).
- Shape: symmetric, right-skewed, left-skewed, or bimodal.
- Outliers and gaps: isolated bars far from the bulk of the data.
Choosing bins honestly
Bin choice is a trade-off between smoothing and detail. Rules of thumb like Sturges', Scott's, or the square-root rule give a starting point — then adjust and confirm that the features you report survive a change of bin width.
Key Formulas
Sturges' rule (bin count)
k = ⌈log₂ n⌉ + 1
n = 40 values → k = ⌈5.32⌉ + 1 = 7 bins.
Bin width
w ≈ (max − min) ÷ k
Range 48–95 with 7 bins → w ≈ 6.7, rounded to 10 for clean edges.
Relative frequency
rf = (bin count ÷ n) × 100%
8 of 40 values in a bin → 20%.
Cumulative frequency
cf(i) = Σ counts of bins 1…i
Running total — the last bin always reaches 100%.
Square-root rule (alternative)
k = ⌈√n⌉
n = 100 values → 10 bins.
Histogram Maker FAQ
Q01How do I make a histogram from my data?
Paste your numbers into the data box — separated by commas, spaces, or new lines — and the histogram is drawn instantly. Adjust the number of bins if you want more or less detail, add a title and axis labels, then download the chart as PNG or SVG.
Q02What is the difference between a histogram and a bar chart?
A histogram shows the distribution of continuous numerical data: values are grouped into intervals (bins), the bars touch, and their order follows the number line. A bar chart compares distinct categories, with gaps between bars that can be reordered freely. Use a histogram for measurements, a bar chart for categories.
Q03How many bins should my histogram have?
A common starting point is Sturges' rule, k = ⌈log₂ n⌉ + 1, which this tool uses automatically — about 6 bins for 30 values or 8 bins for 100. There is no single correct answer: try a few settings and pick the one that shows the shape of the distribution without looking noisy.
Q04What is bin width and how is it calculated?
Bin width is the size of each interval: roughly the data range divided by the number of bins. In automatic mode this tool also rounds the width to a clean value (1, 2, 2.5, 5 × a power of ten) and aligns the bin edges to round numbers, which makes the axis much easier to read.
Q05Can I make a relative frequency histogram?
Yes. Switch the y-axis option to "Relative frequency (%)" and each bar shows the percentage of values in that bin instead of the raw count. The frequency table below the chart always lists counts, percentages, and cumulative percentages side by side.
Q06Can I copy data from Excel or Google Sheets?
Yes. Copy a column (or row) of numbers and paste it straight into the data box — values separated by new lines, tabs, spaces, commas, or semicolons are all understood, including decimals and negative numbers.
Q07How do I download or share the histogram?
Click PNG for a high-resolution raster image (rendered at 2× for crisp slides and documents) or SVG for a scalable vector file you can edit in Figma, Illustrator, or Inkscape; exported files carry a small kanaries.net credit in the corner. You can also copy the PNG straight to your clipboard, or click Share link to copy a URL that reproduces your exact chart — the data travels in the link itself and is never uploaded to a server.
Q08Is this histogram maker free and is my data private?
Yes on both counts. The tool is completely free with no signup and no limits, and it runs entirely in your browser — your data is never uploaded to any server, so it is safe to use with private or sensitive numbers.