# Working Across Sheets

Course: [Excel](https://www.devtutorials.ai/learn/excel) · Section: Worksheets
Source: https://www.devtutorials.ai/learn/excel/worksheets/working-across-sheets

> Reference other sheets, combine data from several sheets, and protect sheets and workbooks. Then build a quarterly summary in the Chapter 6 project.

Once your data is spread across several sheets, like one sheet per month, you often need a summary that brings everything together. Excel formulas can pull data from other sheets, and protection can stop people from accidentally changing your work. In this lesson, you will work with multiple worksheets, reference another sheet in a formula, combine data from several sheets, and protect sheets and the workbook. At the end, you will build a quarterly summary in the Chapter 6 project.

Open the **Excel sandbox** and follow along.

## Multiple worksheets

A common, neat layout is:

- **One sheet per period or group**, all with the **same layout**: `Jan`, `Feb`, `Mar`, each with totals in the same cell.
- **One summary sheet** that pulls the main numbers from the others.

Keeping the layouts the same is what makes cross-sheet formulas simple. If every month’s total is in **B6**, the summary always looks in **B6**.

## Reference another sheet

To use a cell from another sheet, put the **sheet name** and an **exclamation mark** before the address:

=Jan!B6

=Jan!B6*2

='Sales 2026'!B6 (sheet names with spaces need single quotes)

**The easy way:** type `=` in the cell where you want the result, click the other sheet’s tab, click the cell you want, and press **Enter**. Excel writes the reference for you, and takes you back to where you started.

## Using data from multiple sheets

Add values from several sheets with `+`: =Jan!B6+Feb!B6+Mar!B6

Or use functions across sheets: `=SUM(Jan!B2:B5)` adds a range on another sheet, and `=AVERAGE(Jan!B6, Feb!B6, Mar!B6)` averages one cell from each.

In Excel, a **3-D reference** adds the same cell across a run of sheets in one go: `=SUM(Jan:Mar!B6)` adds B6 on every sheet from Jan to Mar. Keep the sheets next to each other in that order.

Cross-sheet formulas update automatically. If you change a number on the `Feb` sheet, the summary changes too.

If you **rename** a sheet, Excel updates every formula that refers to it. If you **delete** a sheet, those formulas show `#REF!`.

## Workbook protection

There are two kinds of protection:

**Protect a sheet** stops people from changing **cells** on that sheet.

1. Go to **Review** > **Protect Sheet** or right-click the sheet tab and choose **Protect Sheet**.
2. Optionally type a password, and choose what people may still do, such as select cells.
3. Click **OK**.

To let people type in some cells, like an input area, first select those cells, open **Format Cells** > **Protection**, and untick **Locked**. Then protect the sheet. Only the unlocked cells can be edited.

**Protect the workbook** stops people from changing the **structure**: adding, deleting, renaming, moving, or hiding sheets.

1. Go to **Review** > **Protect Workbook**.
2. Optionally type a password, and click **OK**.

To remove protection, use **Unprotect Sheet** or **Unprotect Workbook** on the same tab.

Protection prevents **accidents**, not determined people. If you set a password, write it down. Without it, you cannot unprotect your own work.

## Common mistakes

| Mistake | What happens | How to fix it |
|---|---|---|
| Missing `!` in a reference | Excel shows an error | Write `SheetName!Cell` |
| Sheet name with spaces, no quotes | Excel rejects the formula | Use `'Sales 2026'!B6` |
| Different layouts on each sheet | The summary picks up the wrong numbers | Make every sheet’s layout match |
| Deleting a sheet the summary uses | `#REF!` on the summary | Restore the sheet from a saved copy |
| Protecting before unlocking input cells | Nobody can type in the input area | Unprotect, unlock the input cells, protect again |

## Exercise

Click **Reset** in the sandbox header. Rename **Sheet1** to `Shop`, and type in it: **A1** `Sales`, **B1** `400`. Add a second sheet named `Cafe`, and type: **A1** `Sales`, **B1** `250`. Add a third sheet named `Summary`. Then do each task and press **Check**.

## Chapter project

Put Chapter 6 together. You will organize three months of a small business’s expenses into tidy sheets and build a protected quarterly summary.

## What to remember

- Keep the **same layout** on every period sheet, with a separate **summary** sheet.
- Refer to another sheet with `SheetName!Cell`; use quotes for names with spaces.
- Build references by typing `=` and clicking the other sheet’s cell.
- Functions work across sheets: `=SUM(Jan!B2:B4)`.
- **Protect Sheet** locks cells; **Protect Workbook** locks the sheet structure.
- Protection prevents accidents; keep any password safe.

That is the end of Chapter 6. In Chapter 7, you will turn numbers into charts and use conditional formatting.