Wednesday, 20 June 2012

Absolute and Relative Cell Referencing in Excel

There are two important spreadsheet concepts we haven't yet explored: absolute cell references, and relative cell references. We'll explore these two ideas now. First, absolute cell references.

Relative cell references in Microsoft Excel


Take a look at the spreadsheet below (create it for yourself):

A simple spreadsheet


As you can see, it's quite simple. All we are doing is adding together the numbers in cells A1 and A2. We then put the answer in cell B2.


But suppose we wanted to copy the formula in cell B2 to cell B3. Let's try it and see what happens.


  • Click inside cell B2


  • Then click once with your right mouse button


  • A menu pops up


  • With your left mouse button, click Copy


  • Now click inside cell B3


  • Click once with your right mouse button


  • When the menu pops up, click on Paste


  • Your spreadsheet will look like the one below:



The contents have been copied


Excel has done something rather odd. It has given us the answer 25! The sum 20 + 25 clearly does not equal 25, so what's going on?

Well, look inside the formula bar. The formula is now reading = A2 + A3. Yet that was not the formula we pasted from cell B2. We copied and pasted the formula = A1 + A2. So why did Excel copy and paste the wrong formula?

The answer is that we used a Relative cell reference for B2. We have been using Relative cell references throughout this book. This is Excel's default, and it works like this when you copy a formula:

The formula is = A1 + A2. The answer is in cell B2. When copying the formula to cell B3 Excel will note that the cells for the formula start UP one Row, and LEFT one column. When you paste the formula somewhere else, Excel will not paste the formula, but paste this UP one then Left one. So starting at Cell B3, which is where we're pasting to, go UP one Row. This takes you to row 2. Then go one column Left. This takes you to Column A. So the start for the new formula is cell A2. Your formula will now read = A2 + A3. As there is nothing in cell A3, the formula is really = 25 + 0. Which gives the answer 25.

And that's Relative cell referencing.

 

Absolute cell references in Microsoft Excel


If you want to keep a reference to the original cells, A1 and A2, you need to use Absolute cell references. Absolute cell referencing is done with dollar signs.

Change your formula in cell B2 to this:

= $A$1 + $A$2


Then copy and paste the new formula to cell B3. You should now get the answer you were looking for: 45. Your spreadsheet will look like the one below:

Absolute cell reference


To recap, then:






  • When you want to copy and paste formulas, use Absolute cell references


  • To use Absolute referencing, place a dollar sign before the Column letter and a dollar sign before the Row number (You can mix absolute and relative cell references, but we won't go into that.)

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