by Svetlana Cheusheva, updated on
The tutorial shows how to use IFERROR in Excel to catch errors and replace them with a blank cell, another value or a custom message. You will learn how to use the IFERROR function with Vlookup and Index Match, and how it compares to IF ISERROR and IFNA.
"Give me the place to stand, and I shall move the earth," Archimedes once said. "Give me a formula, and I shall make it return an error," an Excel user would say. In this tutorial, we won't be looking at how to return errors in Excel, we'd rather learn how to prevent them in order to keep your worksheets clean and your formulas transparent.
The IFERROR function in Excel is designed to trap and manage errors in formulas and calculations. More specifically, IFERROR checks a formula, and if it evaluates to an error, returns another value you specify; otherwise, returns the result of the formula.
The syntax of the Excel IFERROR function is as follows:
Where:
For example, when dividing two columns of numbers, you may get a bunch of different errors if one of the columns contains empty cells, zeros or text.
To prevent that from happening, use the IFERROR function to catch and handle errors the way you want.
Supply an empty string (") to the value_if_error argument to return a blank cell if an error is found:
=IFERROR(A2/B2, "")
You can also display your own message instead of Excel's standard error notation:
=IFERROR(A2/B2, "Error in calculation")
The following examples show how to use IFERROR in Excel in combination with other functions to accomplish more complex tasks.
One of the most common uses of the IFERROR function is telling the users that the value they are searching for does not exist in the data set. For this, you wrap a VLOOKUP formula in IFERROR like this:
If the lookup value is not in the table you are looking in, a regular Vlookup formula would return the #N/A error:
For your users' piece of mind, wrap VLOOKUP in IFERROR and display a more informative and user-friendly message:
=IFERROR(VLOOKUP(A2, 'Lookup table'!$A$2:$B$4, 2,FALSE), "Not found")
The screenshot below shows this Iferror formula in Excel:
If you'd like to trap only #N/A errors but not all errors, use the IFNA function instead of IFERROR.
For more Excel IFERROR VLOOKUP formula examples, please check out these tutorials:
In situations when you need to perform multiple Vlookups based on whether the previous Vlookup succeeded or failed, you can nest two or more IFERROR functions one into another.
Supposing you have a number of sales reports from regional branches of your company, and you want to get an amount for a certain order ID. With A2 as the lookup value in the current sheet, and A2:B5 as the lookup range in 3 lookup sheets (Report 1, Report 2 and Report 3), the formula goes as follows:
=IFERROR(VLOOKUP(A2,'Report 1'!A2:B5,2,0),IFERROR(VLOOKUP(A2,'Report 2'!A2:B5,2,0),IFERROR(VLOOKUP(A2,'Report 3'!A2:B5,2,0),"not found")))
The result will look something similar to this:
For the detailed explanation of the formula's logic, please see How to do sequential Vlookups in Excel.
As you probably know, array formulas in Excel are meant to perform multiple calculations within a single formula. If you supply an array formula or expression that results in an array in the value argument of the IFERROR function, it'd return an array of values for each cell in the specified range. The below example shows the details.
Let's say, you have Total in column B and Price in column C, and you want to calculate Total Quantity. This can be done by using the following array formula, which divides each cell in the range B2:B4 by the corresponding cell of the range C2:C4, and then adds up the results:
=SUM($B$2:$B$4/$C$2:$C$4)
The formula works fine as long as the divisor range does not have zeros or empty cells. If there is at least one 0 value or blank cell, the #DIV/0! error is returned:
To fix that error, simply do the division within the IFERROR function:
=SUM(IFERROR($B$2:$B$4/$C$2:$C$4,0))
What the formula does is to divide a value in column B by a value in column C in each row (100/2, 200/5 and 0/0) and return the array of results {50; 40; #DIV/0!}. The IFERROR function catches all #DIV/0! errors and replaces them with zeros. And then, the SUM function adds up the values in the resulting array {50; 40; 0} and outputs the final result (50+40=90).
Note. Please remember that array formulas should be completed by pressing the Ctrl + Shift + Enter shortcut.
Now that you know how easy it is to use the IFERROR function in Excel, you may wonder why some people still lean towards using the IF ISERROR combination. Does it have any advantages compared to IFERROR? None. In the bad old days of Excel 2003 and lower when IFERROR did not exist, IF ISERROR was the only possible way to trap errors. In Excel 2007 and later, it's just a bit more complex way to achieve the same result.
For instance, to catch Vlookup errors, you can use either of the below formulas.
In Excel 2007 - Excel 2016:
In all Excel versions:
Notice that in the IF ISERROR VLOOKUP formula, you have to Vlookup twice. In plain English, the formula can be read as follows: If Vlookup results in error, return "Not found", otherwise output the Vlookup result.
And here is a real-life example of an Excel If Iserror Vlookup formula:
=IF(ISERROR(VLOOKUP(D2, A2:B5,2,FALSE)),"Not found", VLOOKUP(D2, A2:B5,2,FALSE ))
For more information, please see Using ISERROR function in Excel.
Introduced with Excel 2013, IFNA is one more function to check a formula for errors. Its syntax is similar to that of IFERROR:
In what way is IFNA different from IFERROR? The IFNA function catches only #N/A errors while IFERROR handles all error types.
In which situations you may want to use IFNA? When it is unwise to disguise all errors. For example, when working with important or sensitive data, you may want to be alerted about possible faults in your data set, and standard Excel error messages with the "#" symbol could be vivid visual indicators.
Let's see how you can make a formula that displays the "Not found" message instead of the N/A error, which appears when the lookup value is not present in the data set, but brings other Excel errors to your attention.
Supposing you want to pull Qty. from the lookup table to the summary table as shown in the screenshot below. Using the Excel Iferror Vlookup formula would produce an aesthetically pleasing result, which is technically incorrect because Lemons do exist in the lookup table:
To catch #N/A but display the #DIV/0 error, use the IFNA function in Excel 2013 and Excel 2016:
=IFNA(VLOOKUP(F3,$A$3:$D$6,4,FALSE), "Not found")
Or, the IF ISNA combination in Excel 2010 and earlier versions:
=IF(ISNA(VLOOKUP(F3,$A$3:$D$6,4,FALSE)),"Not found", VLOOKUP(F3,$A$3:$D$6,4,FALSE))
The syntax of the IFNA VLOOKUP and IF ISNA VLOOKUP formulas are similar to that of IFERROR VLOOKUP and IF ISERROR VLOOKUP discussed earlier.
As shown in the screenshot below, the Ifna Vlookup formula returns "Not found" only for the item that is not present in the lookup table (Peaches). For Lemons, it shows #DIV/0! indicating that our lookup table contains a divide by zero error:
For more details, please see Using IFNA function in Excel.
By now you already know that the IFERROR function is the easiest way to catch errors in Excel and mask them with blank cells, zero values, or custom messages of your own. However, that does not mean you should wrap each and every formula with error handling. The following simple recommendations may help you keep the balance.
This is how you use the IFERROR function in Excel to trap and handle errors. To have a closer look at the formulas discussed in this tutorial, you are welcome to download our sample IFERROR Excel workbook. I thank you for reading and hope to see you on our blog next week.
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