Update all formulas in excel

Change formula recalculation, iteration, or precision in Excel

To use formulas efficiently, there are three important considerations that you need to understand:

Calculation is the process of computing formulas and then displaying the results as values in the cells that contain the formulas. To avoid unnecessary calculations that can waste your time and slow down your computer, Microsoft Excel automatically recalculates formulas only when the cells that the formula depends on have changed. This is the default behavior when you first open a workbook and when you are editing a workbook. However, you can control when and how Excel recalculates formulas.

Iteration is the repeated recalculation of a worksheet until a specific numeric condition is met. Excel cannot automatically calculate a formula that refers to the cell — either directly or indirectly — that contains the formula. This is called a circular reference. If a formula refers back to one of its own cells, you must determine how many times the formula should recalculate. Circular references can iterate indefinitely. However, you can control the maximum number of iterations and the amount of acceptable change.

Precision is a measure of the degree of accuracy for a calculation. Excel stores and calculates with 15 significant digits of precision. However, you can change the precision of calculations so that Excel uses the displayed value instead of the stored value when it recalculates formulas.

As calculation proceeds, you can choose commands or perform actions such as entering numbers or formulas. Excel temporarily interrupts calculation to carry out the other commands or actions and then resumes calculation. The calculation process may take more time if the workbook contains a large number of formulas, or if the worksheets contain data tables or functions that automatically recalculate every time the workbook is recalculated. Also, the calculation process may take more time if the worksheets contain links to other worksheets or workbooks. You can control when calculation occurs by changing the calculation process to manual calculation.

Important: Changing any of the options affects all open workbooks.

Click the File tab, click Options, and then click the Formulas category.

In Excel 2007, click the Microsoft Office Button, click Excel Options, and then click the Formulas category.

Do one of the following:

To recalculate all dependent formulas every time you make a change to a value, formula, or name, in the Calculation options section, under Workbook Calculation, click Automatic. This is the default calculation setting.

To recalculate all dependent formulas — except data tables — every time you make a change to a value, formula, or name, in the Calculation options section, under Workbook Calculation, click Automatic except for data tables.

To turn off automatic recalculation and recalculate open workbooks only when you explicitly do so (by pressing F9), in the Calculation options section, under Workbook Calculation, click Manual.

Note: When you click Manual, Excel automatically selects the Recalculate workbook before saving check box. If saving a workbook takes a long time, clearing the Recalculate workbook before saving check box may improve the save time.

To manually recalculate all open worksheets, including data tables, and update all open chart sheets, on the Formulas tab, in the Calculation group, click the Calculate Now button.

To manually recalculate the active worksheet and any charts and chart sheets linked to this worksheet, on the Formulas tab, in the Calculation group, click the Calculate Sheet button.

Tip: Alternatively, you can change many of these options outside of the Excel Options dialog box. On the Formulas tab, in the Calculation group, click Calculation Options, and then click Automatic.

Note: If a worksheet contains a formula that is linked to a worksheet that has not been recalculated and you update that link, Excel displays a message stating that the source worksheet is not completely recalculated. To update the link with the current value stored on the source worksheet, even though the value might not be correct, click OK. To cancel updating the link and use the previous value obtained from the source worksheet, click Cancel.

Recalculate formulas that have changed since the last calculation, and formulas dependent on them, in all open workbooks. If a workbook is set for automatic recalculation, you do not need to press F9 for recalculation.

Recalculate formulas that have changed since the last calculation, and formulas dependent on them, in the active worksheet.

Recalculate all formulas in all open workbooks, regardless of whether they have changed since the last recalculation.

Check dependent formulas, and then recalculate all formulas in all open workbooks, regardless of whether they have changed since the last recalculation.

Click the File tab, click Options, and then click the Formulas category.

In Excel 2007, click the Microsoft Office Button, click Excel Options, and then click the Formulas category.

In the Calculation options section, select the Enable iterative calculation check box.

To set the maximum number of times Excel will recalculate, type the number of iterations in the Maximum Iterations box. The higher the number of iterations, the more time Excel will need to recalculate a worksheet.

To set the maximum amount of change you will accept between recalculation results, type the amount in the Maximum Change box. The smaller the number, the more accurate the result and the more time Excel needs to recalculate a worksheet.

Note: Solver and Goal Seek are part of a suite of commands sometimes called what-if analysis tools. Both commands use iteration in a controlled way to obtain desired results. You can use Solver when you need to find the optimum value for a particular cell by adjusting the values of several cells or when you want to apply specific limitations to one or more of the values in the calculation. You can use Goal Seek when you know the desired result of a single formula but not the input value the formula needs to determine the result.

Before you change the precision of calculations, keep in mind the following important points:

By default, Excel calculates stored, not displayed, values

The displayed and printed value depends on how you choose to format and display the stored value. For example, a cell that displays a date as «6/22/2008» also contains a serial number that is the stored value for the date in the cell. You can change the display of the date to another format (for example, to «22-Jun-2008»), but changing the display of a value on a worksheet does not change the stored value.

Use caution when changing the precision of calculations

When a formula performs calculations, Excel usually uses the values stored in cells referenced by the formula. For example, if two cells each contain the value 10.005 and the cells are formatted to display values in currency format, the value $10.01 is displayed in each cell. If you add the two cells together, the result is $20.01 because Excel adds the stored values 10.005 and 10.005, not the displayed values.

When you change the precision of the calculations in a workbook by using the displayed (formatted) values, Excel permanently changes stored values in cells from full precision (15 digits) to whatever format, including decimal places, is displayed. If you later choose to calculate with full precision, the original underlying values cannot be restored.

Click the File tab, click Options, and then click the Advanced category.

In Excel 2007, click the Microsoft Office Button, click Excel Options, and then click the Advanced category

In the When calculating this workbook section, select the workbook you want and then select the Set precision as displayed check box.

Although Excel limits precision to 15 digits, that doesn’t mean that 15 digits is the limit of the size of a number you can store in Excel. The limit is 9.99999999999999E+307 for positive numbers, and -9.99999999999999E+307 for negative numbers . This is approximately the same as 1 or -1 followed by 308 zeros.

Precision in Excel means that any number exceeding 15 digits is stored and shown with only 15 digits of precision. Those digits can be in any combination before or after the decimal point. Any digits to the right of the 15th digit will be zeros. For example, 1234567.890123456 has 16 digits (7 digits before and 9 digits after the decimal point). In Excel, it’s stored and shown as 1234567.89012345 (this is shown in the formula bar and in the cell). If you set the cell to a number format so that all digits are shown (instead of a scientific format, such as 1.23457E+06), you’ll see that the number is displayed as 1234567.890123450. The 6 at the end (the 16th digit) is dropped and replaced by a 0. The precision stops at the 15th digit, so any following digits are zeros.

A computer can have more than one processor (it contains multiple physical processors) or can be hyperthreaded (it contains multiple logical processors). On these computers, you can improve or control the time it takes to recalculate workbooks that contain many formulas by setting the number of processors to use for recalculation. In many cases, portions of a recalculation workload can be performed simultaneously. Splitting this workload across multiple processors can reduce the overall time it takes complete the recalculation.

Click the File tab, click Options, and then click the Advanced category.

In Excel 2007, click the Microsoft Office Button, click Excel Options, and then click the Advanced category.

To enable or disable the use of multiple processors during calculation, in the Formulas section, select or clear the Enable multi-threaded calculation check box.

Note This check box is enabled by default, and all processors are used during calculation. The number of processors on your computer is automatically detected and displayed next to the Use all processors on this computer option.

Optionally, if you select Enable multi-threaded calculation, you can control the number of processors to use on your computer. For example, you might want to limit the number of processors used during recalculation if you have other programs running on your computer that require dedicated processing time.

To control the number of processors, under Number of calculation threads, click Manual. Enter the number of processors to use (the maximum number is 1024).

To ensure that older workbooks are calculated correctly, Excel behaves differently when you first open a workbook saved in an earlier version of Excel than when you open a workbook created in the current version.

When you open a workbook created in the current version, Excel recalculates only the formulas that depend on cells that have changed.

When you use open a workbook that was created in an earlier version of Excel, all the formulas in the workbook — those that depend on cells that have changed and those that do not — are recalculated. This ensures that the workbook is fully optimized for the current Excel version. The exception is when the workbook is in a different calculation mode, such as Manual.

Because complete recalculation can take longer than partial recalculation, opening a workbook that was not previously saved in the current Excel version can take longer than usual. After you save the workbook in the current version of Excel, it will open faster.

In Excel for the web, a formula result is automatically recalculated when you change data in cells that are used in that formula. You can turn this automatic recalculation off and calculate formula results manually. Here’s how to do it:

Note: Changing the calculation option in a workbook will affect the current workbook only, and not any other open workbooks in the browser.

In the Excel for the web spreadsheet, click the Formulas tab.

Next to Calculation Options, select one of the following options in the dropdown:

To recalculate all dependent formulas every time you make a change to a value, formula, or name, click Automatic. This is the default setting.

To recalculate all dependent formulas — except data tables — every time you make a change to a value, formula, or name, click Automatic Except for Data Tables.

To turn off automatic recalculation and recalculate open workbooks only when you explicitly do so, click Manual.

To manually recalculate the workbook (including data tables), click Calculate Workbook.

Note: In Excel for the web, you can’t change the number of times a formula is recalculated until a specific numeric condition is met, nor can you change the precision of calculations by using the displayed value instead of the stored value when formulas are recalculated. You can do that in the Excel desktop application though. Use the Open in Excel button to open your workbook to specify calculation options and change formula recalculation, iteration, or precision.

Need more help?

You can always ask an expert in the Excel Tech Community or get support in the Answers community.

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Automatic recalculation of formulas in Excel and manually

Excel by default recalculates all formulas in all sheets of all open books after each introduction of data. The most swell possibility of Excel – is the automatic recounting by formulas. If the sheet contains hundreds or thousands of formulas, the automatic recalculation starts to noticeably slow down the process of working with the program. This ability of spreadsheets increased people’s productivity in dozens of times.

After all, with manual calculation we need to enter each time not only numbers but mathematical operations, do not get confused, constantly placing intermediate results in memory and so on. In our case, we create formulas and then simply change the numbers — everything will automatically be counted again. Well, if the changes are small, it is even better — even to introduce less of data.

Let`s contemplate, how you can customize Excel to improve its performance and unhindered working.

Automatic and manual conversion

For a book that contains hundreds of compound formulas, you can turn against to the recalculation on requirement of a user. For this:

1. You need to enter the formula on a blank sheet (so that you can check how this example works).
2. You need to select the tool: «Formulas» – «Calculation Options» – «Manual».
3. Make sure that now after entering the data into the cell (for example, the number 7 instead of 1 in the cell A2 as in the draught), the formula does not automatically recalculate the result – while the user does not press the F9 key (or SFIFT + F9).

Pay attention! The shortcut F9 performs recalculation in all book formulas on all sheets. There is Combination of hot keys SHIFT + F9 performs recalculation only on the current sheet.

If the sheet does not contain a lot of formulas, that`s why the recalculation can inhibit to Excel. That`s why it makes no sense to use the above described example, but for the future it still worth knowing for you about this possibility: because after all, over time you will have to deal with complex tables with a lot of formulas.

Furthermore, this function can be turned on accidentally and you need to know where to turn it off for the standard operating mode.

How to display to a formula in the Excel cell

In the Excel cells, we can see the result of the calculations only. The formulas themselves can be seen in the formula line (separately). But sometimes we need to simultaneously view all functions in cells (for example, to compare them, and so forth).

To visually display the example of this lesson, we need this sheet containing the formulas:

We change the Excel settings accordingly so that the cells display the formulas, but not the result of their calculation.

To achieve this result, you need to select the tool: «Formulas» – «Show Formulas»» (in the section «Formulas Auditing»). To exit this display mode, you should to select this implement again.

You can also use the shortcut keys combination CTRL + `(above the Tab key). This combination works in switch mode, that is, you need to press this key repeatedly and returns to the normal display mode of calculation results in cells.

The notation. All the above described actions apply only to the mode of displaying cells of one sheet. That is, on other sheets, if necessary, you need to perform these actions again.

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