Conditional formatting is formatting (that you choose) which is applied depending on what is typed in the cell (or the results of a formula). This feature is one of the best things since sliced bread. Take my word for it and take 30 seconds to check it out!!!

For example, if you set up a budget, you could set the formatting to be red if someone exceeds their budget amount. You could also have cells highlight if they are blank but have no formatting if something is typed in the cell if you want to keep track of things that are outstanding (like invitation answers, a column for tracking signatures received, etc.).

Excel 2003

To apply conditional formatting in Excel 2003, first highlight the cells that you want to be conditional, then select Format-Conditional Formatting. Excel will ask what parameters you want to set for the cell. Cell Value or Formula is (fill in the blank: between, equal, not equal, etc.) and then choose either a cell reference (i.e. the budgeted number) or a number that you type. Then click on the Format button and choose whatever formatting you want to be applied to the cells (red, bold, whatever you choose). Click OK.

When you enter a number into that cell, if it falls inside the parameters you set up (within budget) then the text will be normal. If it falls outside (exceeds budget), it will have the formatting you chose.

You can apply up to three parameters (i.e. green color for below 90% of budget, yellow color for 91-100%, red for 101%+).

To remove the conditional formatting, select the cells that have it (or use the tip I discussed in a previous blog posting to select all cells in your worksheet that have it applied: Edit - Go To - Special - Conditional Formatting).

Excel 2007

Conditional Formatting has really been beefed up in Excel 2007 and had some really nifty stuff added. This feature is applied from the Home ribbon. When you select your cells and then click Conditional Formatting, you will soon see that there are a bunch of new options in there. Check them out!

NOTE: On all of these choices, you will see "more rules" on the submenu. This allows you to set even more options on all these various rules. You can also apply more than one set of conditional formatting at a time (i.e. data bars and icon sets together).

Highlight Cell Rules - This is where you go to set straight mathematical rules, like greater than, less than, as well as text based rules, date based rules (great for highlighting past due items), etc. Note the nifty new feature to apply conditional formatting to duplicate values in a column. How handy is that when you want to see at a glance if anything has been duplicated in a long list? :)

Top / Bottom Rules - These are designed to highlight your top or bottom "x" in a column (top 10, etc.)

Data Bars - This applies colored bars to the cells, where the length varies based on the contents, relative to each other (in other words, four cells with the values of 0,2,4,6 would have 25%, 50%, 75%, 100% bars)

Color Scales - This applies colored bars with different shades applied based on the contents, relative to each other (see above).

Icon Sets - This applies colorful icon sets to the cells, based on the contents. Some of these are really cute. Most are based on the green/yellow/red color scheme or black/grey/white.

New Rules - This brings up the same submenu as clicking More Rules on the other submenus. It allows you build a rule from scratch and tweak the settings.

Clear Rules - Go here to clear all rules from selected cells or from the whole worksheet. 

Manage Rules - Go here to clear selected rules. If you have more than one conditional formatting format applied (like the previously mentioned data bars and icon sets for instance), you can select the rules individually, reorder them, and/or delete them. You can also edit individual rules from this submenu.