Excel has a feature that helps you automatically enter data. If you are entering a predictable series (e.g. 1, 2, 3…; days of the week; hours of the day) you can use the AutoFill command to automatically extend the sequence. You can also use this for formulas – set up the formula once, then use the AutoFill to propagate it to the other cells.
For Excel to know how to fill in the series, you usually need to provide two or three examples. In the case of sequences like months, weekdays, and hours, you only need to provide one example.
To use AutoFill with formulas, insert the formula and make sure it works (see Formulas and Functions for more information about working with formulas)
1. Select the cell(s) with the formula and move the cursor over the little block in the lower right corner of the active cell, and the cursor changes to a hairline plus sign (+), as opposed to the usual block plus sign.
2. Click and hold on the fill handle and drag to the right (or down) to fill in the other cells. Excel automatically adjusts the formula for the row it is now on (so, in the example at right, February's total formula would read =SUM(B3:F3) and so on.
A note about using AutoFill with formulas and functions:
If you want a constant reference (for example, each column should be divided by a certain cell's data), add a dollar sign ($) in front that cell's reference in the Formula bar. For example, if =D8*$P$8 is in the Formula bar and you AutoFill from this cell, the next cell would read =D9*$P$8, changing the first cell, but keeping the second cell reference constant – otherwise, it would read =D9*P9.