Line charts: Basic how-to

A simple bar chartTo make a line chart in a spreadsheet, all you strictly need to start with is a set of numbers. Line charts typically compare the values of several items — often but not exclusively the value of a single item at several different points in time. Most stock market charts are line charts with a lot of items.

Remember how I said on pie charts and bar charts that the order didn’t matter very much? It’s true, as long as they’re labeled correctly. (I’ll explain labeling later.) If you have 3 apples and 1 orange, that’s the same as having 1 orange and 3 apples. If Bob read 7 books and Sue read 9, that’s the same as if Sue read 9 and Bob read 7. Since we were comparing items that did not intrinsically have an order of their own it didn’t really matter what order they appeared in.

However, since line charts often compare values over time, all of a sudden it does matter. Let’s say that the values above were the number of fundraiser cookies sold each week. If you were to sort them in increasing order, then 23 would be first, followed by 35, etc. Unfortunately that puts week 5 first, followed by weeks 2, 3, 7, 1, 6, 4, and 8, in that order. For most purposes that just won’t work. Even if it were perfectly labeled, no-one would be able to read a chart like that at first glance. And since conveying information at a glance is what charts are for, that would defeat its purpose.

While you could theoretically make a line chart with only two items, it wouldn’t really look like one. The one pictured above was made with eight randomly generated values. If you want your line to look like mine you can copy the table below and paste it into your favorite spreadsheet.

45
35
36
58
23
55
36
89

After pasting them into a spreadsheet, make sure they’re highlighted them. After that, the steps depend on which program you’re using.

In Excel 97:

  1. Click on the “Insert” menu, then on “Charts”. You might notice that there’s a little icon that looks like a bar chart next to the word “Charts”, and that it’s the same as one of the icons in the toolbar under the menu labels. In the future you could also simply click on that icon in the toolbar.
  2. In the Chart Wizard, choose the “Line” chart type
  3. In the Chart sub-type section on the right, click on the upper left sub-type.
  4. Click on “Finish”

In Excel 2007:

  1. Click on the “Insert” tab
  2. Find the group under this tab that is labeled “charts”. For me, it is the third set.
  3. Click on the icon in this group labeled “Line”. For me it is the first icon in this set.
  4. Click on the first option under “2-D Line” – the one with the dark and light lines criss-crossing each other.

In Google Spreadsheet:

  1. Click on the “Insert” menu, then on “Charts”. You might notice that there’s a little icon that looks like a bar chart next to the word “Charts”, and that it’s the same as one of the icons in the toolbar under the menu labels. In the future you could also simply click on that icon in the toolbar.
  2. In the Chart Editor, click on “Charts”
  3. Click on “Line”.
  4. Click on the first of the three options that appear – the one with jagged lines, rather than curved ones, or the one that looks vaguely like a butterfly.
  5. Click the “insert” button. (It’s off the bottom of my laptop screen, so if you’re working on a small screen you’ll have to grab the Chart Editor window and drag it up until you see it.)

In OpenOffice Calc:

  1. Highlight the two numbers
  2. Click on the “Insert” menu, then on “Chart…” You might notice that there’s a little icon that looks like a line chart next to the word “Chart…”, and that it’s the same as one of the icons in the toolbar under the menu labels. In the future you could also simply click on that icon in the toolbar.
  3. Choose the “Line” chart type.
  4. Choose the “Lines Only” sub-type — it’s the third one in my version, not the first!
  5. Click “Finish”

When you look at your result, the colors will probably be different. Every program has different default colors. In most programs you can change almost everything about your chart: size, colors, category labels, title, backgrounds, etc. I might go into more depth on this later, but in the meantime I encourage you to go ahead and experiment on your own!