gizmobench

Stem and Leaf Plot Maker

Paste or type your numbers and the plot appears beside them, with the key written underneath so it can be read away from this page. The leaf unit is a control rather than a guess: auto takes the finest unit your data needs, and if you choose one too coarse to hold a value the page names that value and the unit that would hold it instead of trimming a digit off it. Negative values keep their sign on the stem, including the stem written -0 where the values from -1 to -9 belong, and the leaves are ordered so the plot reads from the smallest value at the top to the largest at the bottom. Stems can be split in two, at leaves 0 to 4 and 5 to 9, or in five, and a second list opens a back to back plot that shares the stems. Empty stems between your values are drawn rather than closed up, because the gap is part of the shape. Up to 5,000 values across 200 stems, copy the plot and its key as text or save it as SVG, and nothing is uploaded and no account is asked for.

Plotno plot yet

The plot appears here.

No numbers yet.

Every value kept, none roundedNegative stems written outSplit stems and two setsNothing uploaded, no account
Values
0
Stems
0
Leaf unit
Split
Sets
  • 14 values, leaf 123 to 61
    5 stems
  • Split stemssame data, split in two
    10 stems, 0-4 and 5-9
  • Negative values-12, -5, 3
    -1 | 2, -0 | 5, 0 | 3

Nothing to plot yet. Type or paste your numbers on the left, separated by commas, spaces or new lines.

The data, sorted

The same values, smallest first. Every one of them is a leaf on the plot above.

Nothing sorted yet.

Values can be separated by commas, semicolons, spaces, tabs or new lines, so a column copied out of a spreadsheet works as it is. Write 1200 rather than 1,200: a comma always separates one value from the next. Anything that is not a number is counted and named under the stage rather than dropped in silence, and the plot takes up to 5,000 values across 200 stems.

The leaf unit decides what a plot says. One leaf is worth one leaf unit, so at leaf 1 the row 2 | 3 is 23, at leaf 0.1 it is 2.3 and at leaf 10 it is 230. Auto takes the finest unit that holds your data exactly, which is why nothing is rounded: if you pick a unit too coarse to hold a value, the page names the value and the unit that would hold it instead of trimming a digit off. Splitting a stem in two gives it a row for leaves 0 to 4 and a row for leaves 5 to 9, which spreads out a plot whose values crowd onto three or four stems. A negative value keeps its sign on the stem, and the values from -1 to -9 sit on a stem written -0, so -0 | 5 reads as -5. Leaves are listed so the plot runs from the smallest value at the top to the largest at the bottom, which puts the largest digit first on a negative stem, because -19 is smaller than -10.
Accuracy. Exact placement: every value you enter appears once as a leaf, sorted, and the key says what a stem and leaf mean together. Nothing is binned away or rounded, and the leaf unit is the one you choose.

Common questions

How do I read a stem and leaf plot?
Each row is a stem, and every digit to the right of the bar is one value that starts with that stem. The key says how to put the two halves back together: with a key of 2 | 3 = 23, the row 3 | 1 4 4 8 is the four values 31, 34, 34 and 38, and the repeated 4 means 34 appeared twice. Read the rows from top to bottom and you have every value in order, which is what separates this from a histogram: the bars of a histogram have thrown the original numbers away, and these rows have not.
What is the leaf unit, and which one should I choose?
One leaf is worth one leaf unit, so the same row means different things at different units: 2 | 3 is 23 at leaf 1, 2.3 at leaf 0.1 and 230 at leaf 10. Auto is the default and picks the finest unit that holds your data exactly, so whole numbers get leaf 1 and data measured to a tenth gets leaf 0.1. Choose a unit yourself when you want the plot at a particular scale. If the unit you pick cannot hold a value exactly, the page refuses the plot and says which value and which unit would work, because rounding 23.4 down to 23 to make it fit would be a change to your data you did not ask for. Data with more than six decimal places has to be rounded before it is plotted, and the page says so.
How does it handle negative numbers?
The sign stays on the stem, and the plot says so in its key. A value of -12 sits on the stem -1 as the leaf 2, and the key reads -1 | 2 = -12. The values from -1 to -9 have no tens digit, so they sit on a stem written -0, which keeps -5 clearly apart from 5 on the stem 0 below it. Leaves are listed so the plot still runs from the smallest value at the top to the largest at the bottom, which means a negative stem shows its largest digit first: -19 is smaller than -10, so the row reads 9 5 0 rather than 0 5 9.
When should I split the stems?
Split them when your values crowd onto three or four rows and the shape is lost. Split in two gives each stem a row for leaves 0 to 4 and a row for leaves 5 to 9, so a set of 14 values on five stems becomes ten rows and the clusters separate. Split in five gives each stem five rows, at 0-1, 2-3, 4-5, 6-7 and 8-9, which suits a small set spread over one or two stems. Splitting never moves a value: the same leaves are on the plot, on narrower rows, and a note under the plot states which rows take which digits.
Can I compare two sets back to back?
Yes. Switch Sets to Two and a second box appears under the first. Both lists share one column of stems, set A to the left of them and set B to the right, with the leaf nearest the stem the smallest value on its side, so the two halves can be compared row by row. The counts for each set are shown separately above the boxes, the key still says what a stem and a leaf mean, and the 5,000 value ceiling counts both sets together.
How do I enter the data, and what happens to an entry that is not a number?
Separate the values with commas, semicolons, spaces, tabs or new lines, so a column copied out of a spreadsheet and a comma-separated row both work without editing. Decimals, negative numbers, a leading plus and exponent form such as 1e3 are all read. One thing to watch: a comma always separates values, so write 1200 rather than 1,200, or it reads as 1 and 200. Anything that is not a number, a word or a unit stuck to a number such as 5px, is counted and named under the plot rather than dropped without a word.
How many values can it plot?
Up to 5,000 values across 200 stems. Empty stems between your values are drawn rather than closed up, so a very wide range at a fine leaf unit can reach the 200-stem ceiling before the value count matters. When it does, the page says how many stems the data needed and suggests a coarser leaf unit, which is the honest fix: closing the gaps would draw a shape your data does not have.
Can I copy or download the plot?
Copy puts the plot and its key on the clipboard as plain text, spaced the way you see it, which pastes into a document, a worksheet or a message and still lines up in any monospaced font. Download SVG saves the same text as a vector file on the dark background you see here, which scales to any size and opens in Inkscape, Illustrator or Figma. The sorted values under the plot have a Copy button of their own. Your numbers and your settings are kept in this browser's local storage so they are still here when you come back, nothing is uploaded, and there is no account.

Exact placement: every value you enter appears once as a leaf, sorted, and the key says what a stem and leaf mean together. Nothing is binned away or rounded, and the leaf unit is the one you choose.