This week I’ll discuss horizontal alignment.
Horizontal alignment can pretty much always be left, right, or centered. Some spreadsheets might also offer full alignment, where the text is spaced out to fill the entire width of the cell.
If you’re working with text that is shorter than the width of the cell, that horizontal alignment will do is move the text within the cell. Left alignment will have the text starting at the left side of the cell. In most spreadsheets this is the default for text. Right alignment will have the text ending at the right side of the cell. This is usually the default for numbers. Center-alignment, also just called “centered” puts the middle of the text in the middle of the cell.
Some programs also let you “justify” the text, which means that it tries to arrange it so that the text on every line except the bottom one touches both the left and the right edge of the cell. If there’s only line, the this setting doesn’t have any effect.
If you’re working with text that’s longer than the width of the cell the same thing happens, but there’s something else you need to consider. If you have text in the adjacent cells, or if you’re at the edge of a printed page, then the text in cell you’re working will gets visually cut off. It’s still there, but you can’t see it except in the formula bar, and it won’t print out. So if you had the entire alphabet in a cell, you might only see “abcdefghi” in a left-aligned cell. You might see “ijklmnopq” with a small bit of “r” showing as well in a center-aligned cell, and “rstuvwzyz” in a right-aligned cell.
There’s a lot of information you can subtly convey using horizontal alignment. I often switch between right and left alignment when I’m switching between a list of items and their total or other summary, or between a category and its subcategories. I only do this for the row labels, not the information, so if there are a lot of columns then it helps to also use a font change or background shading to carry the distinction across. If there’s only two columns — one for labels and one for information — then the alignment change in the labels column is enough to tell the eye what it’s looking at.
Another thing you can do with horizontal alignment is to make it easier to scan through a lot of things that have different widths. Take, for example, a list of dates. If the dates had the months all spelled out, which you might want to do in order to make it easier to recognize/remember, then they’d all be different widths. “May 1, 2012” is, after all, much shorter than “September 30, 2012”. So if you’re measuring a short span or recurring event that is best expressed in months or days, such as a list of birthdays of people you know, then you might want to have it aligned to the left. That way the eye scanning down reads the month first, followed by the day if the month is the one the reader wants. If you’ve got a pretty broad span however, such as the birthdays of major historical figures, then the year is honestly more important. In that case you’d want to have it right-aligned, so the eye can skim down the list of years, and then go to the start of the line once it finds the correct one.
I also frequently center-align columns of information and their headers, especially if all the entries are more or less the same length. This helps visually unify the column, which lessens the chance of the eye skipping and mistaking which column the numbers belong to.
The big exception to this is when the information is currency or other information with decimal places and a differing number of digits before the decimal point. To me, unless the decimal points all line up it just looks funny, and distracts my eye. For example, look at this excerpt from the financial report, with the numbers center-aligned. Is it harder to read for you? It sure is for me! So I leave them all right-aligned unless there’s a really good reason not to.