When you enter a cell reference into the formula bar, you can press the F4 button to make the reference either absolute, mixed, or relative. This helps your formula work as expected when you copy the formula to another location.

- Absolute references look like this: $A$1, where the dollar signs ($) indicate that when copying a formula to another cell, Excel should not change the reference to cell A1.
- Mixed references look either like $A1 or A$1. The dollar sign ($) in $A1 means that if you copy the formula, it will always reference column A, however if you copy the formula down, it will change the row number relative to its new location. The dollar sign ($) in A$1 does just the opposite. Copying a formula will always reference row number 1, however it will change the column letter relative to its new location.
- Relative references look like this: A1, where there are no dollar signs ($). This indicates that both the column letter and the row number will change when copying a formula relative to the new location.

Always check to see if your formula is using absolute, mixed or relative cell references prior to copying them to another location.