Stem-and-Leaf Plot Maker

What are stems and leaves?

A stem-and-leaf plot splits each number into a leading part, the stem, and a final digit, the leaf. It groups nearby values while retaining the individual observations. For whole numbers, 12 | 3 = 123: the stem is 12 and the leaf is 3. Each repeated value gets its own leaf.

For a small dataset this can make clusters, gaps and unusual observations easy to inspect. A histogram is usually easier to read for many observations or a very wide range, but its bars do not preserve the individual values.

Worked example

For 12, 14, 14, 21, 25, 32, the leaves beside stem 1 are 2, 4, 4; beside stem 2 they are 1, 5; beside stem 3 the leaf is 2. With leaf unit 1, the key is 1 | 2 = 12.

There are six leaves because there are six observations. The two leaves marked 4 in the first row represent two separate values of 14. A long row indicates more observations in that range; it does not mean the values themselves are larger.

Decimals and negative numbers

The shared leaf unit is the smallest decimal place needed by any entered value, up to six places. With 1.2 and 1.25, the leaf unit is 0.01: 12 | 0 = 1.20 and 12 | 5 = 1.25. Unnecessary trailing zeros do not change the unit. Integer-only data uses a leaf unit of 1.

A minus sign applies to the entire observation: at leaf unit 1, −1 | 2 = −12, not −8. Negative rows have descending leaves so the underlying numbers remain sorted from smallest to largest. The stem −0 holds negative observations nearest zero; for example, at leaf unit 0.1, −0 | 3 = −0.3. It is a stem label, not a claim that zero itself is negative.

Empty stems between the minimum and maximum are retained. Long rows wrap on smaller screens and in PNG and SVG exports; a wrapped line continues the same stem. The expandable underlying-data table lists all original numerical values in ascending order.

Input limits and privacy

Use up to 1,000 observations between −1,000,000,000 and 1,000,000,000. Spaces, commas, tabs, semicolons and new lines separate observations. Use a decimal point and omit thousands separators: 1000 is one value, while 1,000 is read as two. A first-line Value, Values or Data header and quoted numeric cells are supported; other headers must be removed. Every numeric cell belongs to the same dataset.

Scientific notation is accepted when its expanded value fits the six-decimal-place limit. Values that would need rounding are rejected, not changed. Datasets needing more than 100 stem rows are also rejected: use a histogram, or make a deliberate rounding decision before entering the data. Rescaling units can help with the magnitude limit. This first version does not split stems or compare two datasets side by side.

Processing and PNG/SVG creation take place in your browser. Opening another chart passes the values locally, without putting them in the URL or changing your saved charts. This plot is not automatically saved when you leave the page.

Explore the same data another way

Use the Statistics Calculator for mean, median and spread, a Box Plot for quartiles and potential outliers, or a Histogram for frequency bins. A distant observation deserves investigation; its position alone is not proof that it is an error.

For more on the method, see NIST’s stem-and-leaf plot reference and OpenStax’s introduction to stemplots.

Lessons and printable worksheets

Practise with original sample data, worked answers, and free classroom worksheets.

• Mean vs Median: Which Average Should You Use?
• Stem-and-Leaf Plots: A Step-by-Step Guide with Practice Questions