Number Sequence in Excel: Fill Series or Use a Formula

To create a number sequence in Excel, enter the first two numbers, select both cells, and drag the fill handle to extend the pattern. For a sequence that updates automatically, enter a formula such as =SEQUENCE(10,1,1,1) in a blank cell; in Microsoft 365 or Excel 2021 and later, it returns the numbers 1 through 10 down the column. Use the fill handle for a quick list, or a formula when you want the sequence to respond to changes.

The steps below are for Excel for Microsoft 365 on Windows. They cover counting by ones, creating a different interval, and generating a sequence with a formula. The same fill-handle approach is available in Excel for Mac and Excel for the web, though ribbon layouts and formula availability can vary.

What You’ll Need

An Excel worksheet with an empty area large enough for your sequence.
A starting number and, if you want a repeating interval such as 5, 10, 15, the amount to add each time.
Excel 2021 or Microsoft 365 if you plan to use the SEQUENCE function. The fill handle and Fill Series options are alternatives for older desktop versions.

Step-by-Step

Choose where the sequence should go. Click the cell where the first number belongs. A vertical sequence fills down a column; a horizontal sequence fills across a row. Check that the cells in the direction you plan to fill are empty, because filling can replace existing contents. If the values will be used in a table, leave a header row and start the numbers beneath it.
Enter the first value. Type the number you want to begin with, such as 1, 0, or 100, and press Enter. A single starting value is enough for a simple count by ones, but Excel may copy that value rather than infer an interval when you drag. Entering two values is the clearest way to show Excel the pattern.
Enter a second value if the interval is not one. In the cell directly below the first value, type the next number. For example, enter 1 and then 2 to count by ones, 10 and then 15 to count by fives, or 20 and then 17 to count down by threes. Excel uses the difference between those values to continue the sequence. For a horizontal list, put the two starting values in neighboring cells in the same row.
Select the starting value or values. Click and drag across both starting cells, such as A1:A2, when you want Excel to infer a pattern. For a simple sequence increasing by one, you can select just the first cell and drag; if Excel repeats the value, undo and select two values instead. Make sure the selected cells contain numbers, not numbers stored as text.
Drag the fill handle. Move the pointer to the tiny square at the bottom-right corner of the selection. When the pointer changes to a small black plus sign, drag down or to the right until the sequence reaches the intended last cell, then release. The first two values remain in place and Excel fills the selected range with the continuation. If you need an exact number of rows, count the starting cells as part of the total: dragging from A1 through A20 produces 20 cells.
Check the result and choose a fill option if needed. Review the last few entries to confirm the interval is right. If Excel copies the starting number instead of continuing it, click the Auto Fill Options button that appears by the filled range and select Fill Series. You can also undo with Ctrl+Z and repeat the drag after selecting two starter values. On Mac, use Command+Z to undo.
Use the Fill Series command for a precise endpoint. Enter the first number in a cell and select the range you want to fill, including that cell. On Windows, choose Home > Editing > Fill > Series. In the dialog, choose Rows or Columns, select Linear for a regular addition pattern, enter a Step value, and enter a Stop value if you want Excel to stop at a particular number. Select OK. For example, a start of 5, step of 5, and stop of 30 fills 5, 10, 15, 20, 25, and 30, provided the selected range is large enough. If the stop value does not fall exactly on the pattern, Excel fills only values that fit the step and stop limit.
Generate a dynamic list with SEQUENCE. If you want a formula-driven result, click an empty cell with enough clear space below it or beside it. With the first result intended for A1 and a 10-row, one-column sequence starting at 1 with an increment of 1, enter =SEQUENCE(10,1,1,1). Press Enter; the formula spills the values 1 through 10 into neighboring cells. The arguments specify rows, columns, starting number, and step. To create the same sequence across a row instead, set the row count to 1 and the column count to 10: with the first result intended for A1, use =SEQUENCE(1,10,1,1). SEQUENCE is available in Microsoft 365 and Excel 2021 or later; in Excel for the web it works when supported by the account and workbook.
Build a sequence that depends on a cell value. A SEQUENCE formula can use a worksheet cell to determine how many numbers to return. With the desired count entered in B1, and the first result intended for A1, use =SEQUENCE(B1,1,1,1). If B1 contains 6, the formula spills 1 through 6; changing B1 to 8 extends the result to 1 through 8, as long as the extra spill cells are clear. To make a fixed interval, change the final argument. With the first result intended for A1, use =SEQUENCE(6,1,10,5) to return 10, 15, 20, 25, 30, and 35 down the column.
Use a basic formula if SEQUENCE is unavailable. This method works in older Excel versions too. Put the starting number in A1. In A2, where A1 contains the first value and the next value should increase by one, enter =A1+1, then copy A2 down as far as needed using the fill handle or copy and paste. For a different interval, add that amount instead: with 10 in A1 and a step of 5, enter =A1+5 in A2 and copy down. Each formula refers to the cell directly above, so the values continue the pattern. If you need to keep only the results, copy the generated cells and use Paste Special > Values.

Common Mistakes

Selecting only one starter value for a custom interval: a single value does not tell Excel whether to count by 1, 5, or another amount. Provide two values with the desired difference, or use Fill Series and set the step explicitly.

Dragging the wrong square: the fill handle is the small square at the lower-right corner of the selection, not the cell border. If the selection moves instead of filling, undo and try again from the handle.

Overlooking occupied cells: a fill operation can overwrite existing data. Confirm the destination range is empty before dragging or using a formula that spills.

Expecting SEQUENCE to overwrite cells: a dynamic array formula needs a clear spill range. If any cell in that output area has content, Excel may show a spill error rather than replace it.

Confusing a number with text: an entry preceded by an apostrophe, or imported with text formatting, may not behave as a numeric starting value. Check the cell alignment and number format, or re-enter the value as a number.

Tips

Use the fill handle when you need a one-time list and the interval is easy to show with two values. Use Fill Series when you know the exact step or stopping number and want to set those options directly. Use SEQUENCE when the list should resize based on an input, such as a count stored in another cell.

For a list of dates, enter two dates with the interval you want and drag; Excel recognizes dates as a series. If you want dates one week apart, enter dates seven days apart as the two examples. Fill Series also includes a Date option for date-based patterns.

To display identifiers with leading zeros, remember that ordinary numeric formatting may hide zeros typed at the start. You can apply a custom number format, such as 00000, to display 1 as 00001 while retaining a numeric value. For identifiers that must be treated as text, consider whether sorting or calculations will be needed before choosing a format.

When you need a static list, copy the filled or formula-generated cells and paste values so later edits to the original inputs do not change the list. Before sorting a sequence alongside related records, select the entire table rather than just the number column to keep each number with its corresponding row.

Troubleshooting

The drag repeats the same number. Undo, enter a second starter value that demonstrates the intended interval, select both values, and drag again. If you are using one starting value, use the Auto Fill Options button and choose Fill Series rather than Copy Cells.

The sequence stops too soon or goes too far. Drag to the correct last cell, or use Fill Series with a Stop value and a sufficiently large selected range. Remember that the starting cell counts toward the sequence length. For example, a 12-number list beginning in A1 ends in A12, not A13.

SEQUENCE returns a spill error. Clear any contents, merged cells, or other obstruction from the intended output area, then recalculate or re-enter the formula. If the formula is inside an Excel Table, move it outside the table or use a fill-handle method, because dynamic array formulas do not spill within table cells in the usual way.

Excel displays the formula as text or does not calculate it. Change the cell format from Text to General, then re-enter the formula. Also confirm that the first character is an equals sign and that the formula uses commas between arguments. If calculation is set to Manual, choose Formulas > Calculation Options > Automatic, or press F9 to recalculate.

The fill handle is missing. In desktop Excel for Windows, open File > Options > Advanced and check Enable fill handle and cell drag-and-drop under Editing options. Excel for Mac has corresponding settings in Excel > Preferences or Settings, depending on the release. In Excel for the web, use the visible cell handle if available, or enter a formula and copy it into the required cells.

Frequently Asked Questions

How do I start a sequence at zero? Enter 0 as the first value and 1 as the second, then select both and fill. With the first result intended for A1, =SEQUENCE(10,1,0,1) returns 0 through 9.

How do I count by twos or another amount? Enter two starter values that show the interval, such as 2 and 4, and drag. Or use Fill Series with a Step value of 2. With the first result intended for A1, =SEQUENCE(5,1,2,2) returns 2, 4, 6, 8, and 10.

Can I make a sequence go backward? Yes. Use two descending starter values, such as 10 and 9, or specify a negative step. With the first result intended for A1, =SEQUENCE(5,1,10,-1) returns 10, 9, 8, 7, and 6.

Why is SEQUENCE not recognized? The function requires Excel 2021 or Microsoft 365, and is not available in some older perpetual versions. Use the fill handle, Fill Series, or a formula such as the cell-above method instead.

Will a formula-generated sequence update automatically? A SEQUENCE formula recalculates when its arguments or referenced cells change, and its spilled range can grow or shrink accordingly. A sequence created by dragging is a set of cell values, so it does not automatically change when you edit the original starting value.

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Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

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