Excel’s Autofill feature allows you to quickly fill cells with repetitive or patterned data like numbers, dates, times, weekdays, months, years, formulas, and more. Using Autofill can save you significant time compared to manually entering data repeatedly.
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What is Autofill?
Autofill is an Excel feature that automatically fills cells based on the contents of adjacent cells. For example, if you type “1” in cell A1 and “2” in cell A2, then select those cells and drag the fill handle down, Excel will automatically fill the sequence of numbers.
Key things to know about Autofill:
- Works by detecting patterns and sequences in existing data
- Activated by dragging the fill handle (small square in bottom-right of selected cells)
- Can fill numbers, dates, times, weekdays, months, formulas, custom lists, and more
- Options to control exact fill behavior available via Auto Fill Options button
Autofill in action
Autofill in action – image from [search result 25]
Types of Data Autofill Can Populate
You can use Autofill to quickly populate cells with various types of repetitive or patterned data:
Numbers
- Sequences: 1, 2, 3, 4, 5…
- Even/odd: 2, 4, 6… or 1, 3, 5…
- Multiples: 5, 10, 15…
Dates
- Sequences: 1/1/2023, 1/2/2023…
- Weekdays: Monday, Tuesday…
- Months: January, February…
- Years: 2023, 2024…
Times
- Hours: 8:00 AM, 9:00 AM…
- Minutes/seconds: 0:00, 0:01, 0:02…
Formulas
- Apply same formula to multiple cells
- Adjust cell references automatically
Text Values
- Weekdays
- Months
- Custom lists like product names
How To Use Autofill
Using Autofill to populate cells is simple:
- Enter beginning values in starting cells
- Numbers: enter 1st two values that define pattern
- Dates: enter start date
- Text: enter one value
- Select the cells with starting values
- Position mouse over fill handle in corner of selection
- Drag the fill handle to populate additional cells
- Drag down to fill vertically
- Drag across to fill horizontally
See [search result 1] for a video demonstration.
Controlling Fill Behavior
If the automatic fill behavior isn’t what you want, click the Auto Fill Options button that appears after dragging to select another fill option like:
- Copy Cells
- Fill Series
- Fill Formatting Only
- Fill Without Formatting
See [search result 2] for more fill handle tips.
Autofilling Formulas
Autofill is extremely useful for applying the same formula to an entire column or row while automatically adjusting the cell references.
For example, if cell A1 contains the formula =B1*2, you can select cell A1 and drag the fill handle down to apply that formula to cells A2, A3, etc. automatically.
The cell references update relative to the row for each cell:
- A1 =
B1*2 - A2 =
B2*2 - A3 =
B3*2
See [search result 5] for more on autofilling formulas.
Data Validation With Flash Fill
Excel’s Flash Fill feature can automatically detect patterns in existing data and extract or combine data accordingly, saving you from manual clean up.
For example, if you have first and last names separated by spaces in cells, Flash Fill can automatically format them into a standard format.
See [search result 1] for a Flash Fill demo.
Random Sampling With Formulas
You may need to select a random sample from a large dataset. This can be easily accomplished using Excel’s RAND() and sorting functions:
- Insert
=RAND()formula to add random number to each row - Copy random number formula down for every row
- Sort entire dataset by the random number column
- Select the first X rows for your random sample size
See [search result 11] for more details.
Tips For Effective Use
Follow these tips when using Autofill:
- Start fill series with 2-3 initial cells to establish pattern
- Use Auto Fill Options to control fill behavior
- Adjust cell formatting if fill formatting is unwanted
- Begin with labels in first column when filling formulas
- Use dollar signs (
$) to absolute reference cells - Double-click fill handle to populate full column/row instantly
Conclusion
Mastering Excel’s Autofill feature can help you work faster and more efficiently when entering repetitive datasets or applying formulas across columns and rows.
With some practice, you’ll know how to leverage Autofill to populate numbers, dates, times, formulas, and custom lists quickly with clean, automated data.
Combined with other features like Flash Fill and sorting, Autofill gives you the power to clean up and transform raw datasets for analysis. Take advantage of these tools to save time on data entry!
