statcompute

Charts

Line Graph Maker

Plot a sequence — one series or several — with the values labelled and the data table underneath.

Also called line plot generator, line graph generator, line chart maker.

Updated August 2026Runs in your browser — nothing is uploadedVerified against R
A header row names the series. Paste straight from a spreadsheet.

The calculation runs in your browser, so this box needs JavaScript. The formula, the worked example and the interpretation below do not.

01

How to read this result

A line asserts that the space between points means something. That is true for time, distance and any ordered continuous variable, and false for categories — which is why unordered categories belong in a bar chart.

Direct labels beat a legend. Each line is labelled at its right-hand end, so the reader never has to look away from the chart and back. Colour is a secondary channel here, not the only one.

No dual axes. Two series on two different y-scales let you put the crossing point anywhere you like by choosing the scales, which makes the chart an argument rather than a measurement. Two charts, or both series indexed to a common base, say the same thing honestly.

A non-zero y-axis is defensible here, unlike on a bar chart: position rather than length carries the value. But say so, because a truncated axis still exaggerates the visual size of small changes.

02

The formula

change=ylastyfirst%Δ=ylastyfirst|yfirst|

The first and last values, and the change between them, are reported for every series — usually the first thing anyone wants from a line chart.

03

Worked example

Two series over six months

Six months of sales and costs. Both rise; the question is whether the gap between them is widening.

month 1: 100, 80 · 2: 112, 85 · 3: 108, 83 · 4: 125, 90 · 5: 131, 95 · 6: 142, 98

  1. First and last for each series.
    sales 100 → 142; costs 80 → 98
  2. The change in each.
    sales +42 (+42%); costs +18 (+22.5%)
  3. The gap at each end.
    month 1: 20; month 6: 44
  4. So the margin has more than doubled in absolute terms.
    gap +120%
points 6series 2sales change +42%costs change +22.5%

Both lines are drawn on one axis, so the widening gap is visible directly. On a dual axis the same data could be made to show the lines converging, diverging or crossing — which is the whole reason this tool does not offer one.

Checked against arithmetic.

The calculator above is loaded with these numbers by the Load the worked example button.

04

Assumptions, and when to use something else

The x values must be ordered and the intervals between them should be meaningful. Unequally spaced points drawn as if equally spaced distort the slope, which is the most common error in quickly-made line charts.

Missing values are left as gaps rather than interpolated, because joining across a gap invents data that was not collected.

  • The categories are not orderedBar chart makerA line between unordered categories asserts a sequence that does not exist.
  • You want to show the relationship between two variablesScatter plot makerFor x against y with no time dimension, points rather than a line.
  • You want to quantify the trendLinear regressionA fitted slope with a standard error, rather than a line drawn by eye.
05

Questions people ask

Can I plot two series with very different scales?

Not on one axis, and this tool deliberately does not offer a second one. A dual axis lets you place the crossing point anywhere by choosing the scales. Index both series to 100 at the start, or draw two charts.

Should the y-axis start at zero?

Not necessarily. On a line chart the value is read from position rather than length, so a zoomed axis can be the honest choice when the variation is small relative to the level. Say what the axis shows, and never do it on a bar chart.

What if some values are missing?

Leave the cell out and the line breaks there. Interpolating across a gap draws data you do not have, which is worse than an honest hole.

How do I download the chart?

Every chart draws to a canvas in your browser. Use the download button for a PNG, or right-click the image and save it. Nothing is uploaded to produce it.