# Calc widget > A small calculator on your desk. Click the keys to add, subtract, multiply and divide. The answer shows as you go, and the sum stays with the widget. Source: https://plexiidesk.com/help/widget-calc Section: Widgets > Numbers and data Plans: All plans Updated: 2026-10-10 Calc is a small calculator that sits on a desk. Use it for the quick sums that come up while you work: checking a total on a quote, splitting a cost, or working out how many days are left. You click the keys on its keypad, the answer shows as you go, and the sum is kept with the widget, so it is still there when you come back. More about this widget ## Before you start - Calc is on every plan. - You need a desk open. ## Add a Calc The quickest way is its key: 1. Open the desk you want the Calc on. 2. Click an empty part of the desk, so that no widget is selected and you are not typing. 3. Press `C`. A Calc appears straight away. Or use the menu: 1. Click **Add widget** in the centre of the header. 2. Click **Calc**. The grey letter beside it is its key. The **Add widget** menu groups widgets into columns by what they are for. **Calc** is in the **Numbers & data** column. You can also type calc in the search box at the top of the menu and press `Enter`. A new Calc is a narrow widget (208 × 300) with a display at the top and the keypad below it. ### Other ways to add one - **The command palette.** Press `⌘` `K` on a Mac or `Ctrl` `K` on Windows, type calc and choose **Add Calc**. - **The tool rail.** Rest the pointer on the tool rail at the right of the desk, click **Add widget**, then open **Advanced** (more objects). Calc is listed under **Tools**. See [The tool rail on the right of a desk](https://plexiidesk.com/help/desk-tool-rail). ### Change the C key 1. Press `⌘` `/` on a Mac or `Ctrl` `/` on Windows to open **Keyboard shortcuts**. 2. Under **Canvas quick-add**, click the key beside **Add Calc**. 3. Press the letter you want to use instead. Press `Backspace` instead of a letter to turn the key off. See [Add widgets with a single key](https://plexiidesk.com/help/quick-add-keys). ## Work out a sum 1. Click the number keys, and **.** for a decimal point, to enter the first number. 2. Click **+**, **−**, **×** or **÷**. 3. Enter the next number. Keep going for as many steps as you need. 4. Click **=**. The small line at the top of the display shows the sum you are building. The large line underneath shows its answer, worked out as you go. When you click **=**, the answer replaces the sum, so you can carry on from it. For example, after 12 × 4 = you can click + 6 = to get 54. ### The other keys - **C** clears the sum and starts again. - **⌫** deletes the last digit, point or operator you entered. - **%** gives the remainder after dividing. For example, 10 % 3 is 1. > **Tip:** > To find a percentage of a number, multiply by the percentage as a decimal. For 15% of 80, click 80 × 0.15 =, which gives 12. ### How the answer is worked out - Multiplying and dividing are done before adding and subtracting, the usual order for sums. So 2 + 3 × 4 is 14. - Answers are rounded to 10 decimal places. - While a sum is unfinished, for example when it ends in **+**, the large line shows **error**. It changes to the answer as soon as you enter the next number. - A sum that has no answer, such as dividing by zero, also shows **error**. Clicking **=** then leaves the sum as it is, so you can fix it with **⌫** or start again with **C**. ## Your sum is kept The Calc saves its sum as you work. When you move to another desk, or close and reopen PlexiDesk, the Calc shows the same sum and answer. Each Calc keeps its own, so you can have one for each thing you are working out. ## The title bar The title bar's buttons appear when you rest the pointer on the Calc. The ones you are most likely to use are: - **Rename** (the pencil), or double-click the name, to call the Calc after what it is for, such as "Trip costs". - **Pin**, to keep the Calc in a corner of the window while you move around a large desk. Pick **Top left**, **Top right**, **Bottom left** or **Bottom right**. Click the pin again and choose **Unpin — return to canvas** to put it back. - **−** and **+**, to make it smaller or larger. - **×**, to remove it from the desk. PlexiDesk asks **Remove from the desk?** first. Right-click the title bar for the menu every widget shares. See [The controls on every widget](https://plexiidesk.com/help/widget-title-bar). The title bar starts with an **AI** button (the sparkle). Calc has no AI of its own, so on a Calc this button opens the Plexii panel, where you can ask Plexii a question. See [Use a widget's AI button](https://plexiidesk.com/help/widget-ai). ## Sharing When you publish a live view of a desk, a Calc appears as a picture of the widget, or as a placeholder when there is no picture. Visitors cannot use it. See [Publish a live view of a desk](https://plexiidesk.com/help/share-live-web-view). ## Good uses - **Quick checks while you read.** Keep a Calc beside a quote, an invoice or a document and check its totals as you go. - **Splitting a cost.** Divide a bill between people, or a budget across months. - **A calculator that stays put.** Pin a Calc to a corner of a busy desk so it is always in reach. - **Working figures you want to keep.** For sums you want to label, save and change later, use a [Spreadsheet](https://plexiidesk.com/help/widget-spreadsheet). For totals worked out from a table, use a [Chart](https://plexiidesk.com/help/widget-chart) set to KPI, or a [Metrics widget](https://plexiidesk.com/help/widget-metrics). ## Common questions **I pressed C on my keyboard and got a new Calc.** `C` is the key for adding a Calc to the desk. To clear the sum in a Calc, click the **C** key on its keypad. **Can I type numbers with my keyboard?** Calc works from its own keypad. Click the keys to enter your sum. **Why does the display say error?** The sum is unfinished, for example it ends in an operator, or it has no answer, such as dividing by zero. Enter the next number, or click **⌫** or **C**. **Where is the percent key?** The **%** key gives the remainder after dividing. To work out a percentage, multiply by it as a decimal, for example 80 × 0.15 for 15% of 80. **Does Calc keep a list of my past sums?** It keeps the sum on its display. To keep several results, add another Calc, or use a [Spreadsheet](https://plexiidesk.com/help/widget-spreadsheet). ## Related tasks - [Numbers and data widgets](https://plexiidesk.com/help/widgets-numbers-and-data) - [Add widgets with a single key](https://plexiidesk.com/help/quick-add-keys) - [Add a widget to a desk](https://plexiidesk.com/help/add-a-widget) - [Spreadsheet widget](https://plexiidesk.com/help/widget-spreadsheet) - [Build a dashboard on a desk from a table](https://plexiidesk.com/help/widgets-dashboard) - [The controls on every widget](https://plexiidesk.com/help/widget-title-bar)