Index array from excel

The INDEX function returns the value at a given location in a range or array. INDEX is a powerful and versatile function. You can use INDEX to retrieve individual values, or entire rows and columns. INDEX is frequently used together with the MATCH function. In this scenario, the MATCH function locates and feeds a position to the INDEX function, and INDEX returns the value at that position. 

In the most common usage, INDEX takes three arguments: array, row_num, and col_num. Array is the range or array from which to retrieve values. Row_num is the row number from which to retrieve a value, and col_num is the column number at which to retrieve a value. Col_num is optional and not needed when array is one-dimensional.

In the example shown above, the goal is to get the diameter of the planet Jupiter. Because Jupiter is the fifth planet in the list, and Diameter is the third column, the formula in G7 is:

=INDEX(B5:E13,5,3) // diameter of Jupiter

The formula above is of limited value because the row number and column number have been hard-coded. Typically, the MATCH function would be used inside INDEX to provide these numbers. For a detailed explanation with many examples, see: How to use INDEX and MATCH.

Basic usage

INDEX gets a value at a given location in a range of cells based on numeric position. When the range is one-dimensional, you only need to supply a row number. When the range is two-dimensional, you’ll need to supply both the row and column number. For example, to get the third item from the one-dimensional range A1:A5:

=INDEX(A1:A5,3) // returns value in A3

The formulas below show how INDEX can be used to get a value from a two-dimensional range:

=INDEX(A1:B5,2,2) // returns value in B2
=INDEX(A1:B5,3,1) // returns value in A3

INDEX and MATCH

In the examples above, the position is «hardcoded». Typically, the MATCH function is used to find positions for INDEX. For example, in the screen below, the MATCH function is used to locate «Mars» (G6) in row 3 and feed that position to INDEX. The formula in G7 is:

=INDEX(B5:E13,MATCH(G6,B5:B13,0),3)

MATCH provides the row number (4) to INDEX. The column number is still hardcoded as 3.

INDEX and MATCH with horizontal table

In the screen below, the table above has been transposed horizontally. The MATCH function returns the column number (4) and the row number is hardcoded as 2. The formula in C10 is:

=INDEX(C4:K6,2,MATCH(C9,C4:K4,0))

For a detailed explanation with many examples, see: How to use INDEX and MATCH

Entire row / column

INDEX can be used to return entire columns or rows like this:

=INDEX(range,0,n) // entire column
=INDEX(range,n,0) // entire row

where n represents the number of the column or row to return. This example shows a practical application of this idea.

Reference as result

It’s important to note that the INDEX function returns a reference as a result. For example, in the following formula, INDEX returns A2:

=INDEX(A1:A5,2) // returns A2

In a typical formula, you’ll see the value in cell A2 as the result, so it’s not obvious that INDEX is returning a reference. However, this is a useful feature in formulas like this one, which uses INDEX to create a dynamic named range. You can use the CELL function to report the reference returned by INDEX.

Two forms

The INDEX function has two forms: array and reference. Both forms have the same behavior – INDEX returns a reference in an array based on a given row and column location. The difference is that the reference form of INDEX allows more than one array, along with an optional argument to select which array should be used. Most formulas use the array form of INDEX, but both forms are discussed below. 

Array form

In the array form of INDEX, the first parameter is an array, which is supplied as a range of cells or an array constant. The syntax for the array form of INDEX is:

INDEX(array,row_num,[col_num])

• If both row_num and col_num are supplied, INDEX returns the value in the cell at the intersection of row_num and col_num.
• If row_num is set to zero, INDEX returns an array of values for an entire column. To use these array values, you can enter the INDEX function as an array formula in horizontal range, or feed the array into another function.
• If col_num is set to zero, INDEX returns an array of values for an entire row. To use these array values, you can enter the INDEX function as an array formula in vertical range, or feed the array into another function.

Reference form

In the reference form of INDEX, the first parameter is a reference to one or more ranges, and a fourth optional argument, area_num, is provided to select the appropriate range. The syntax for the reference form of INDEX is:

INDEX(reference,row_num,[col_num],[area_num])

Just like the array form of INDEX, the reference form of INDEX returns the reference of the cell at the intersection row_num and col_num. The difference is that the reference argument contains more than one range, and area_num selects which range should be used. The area_num is argument is supplied as a number that acts like a numeric index. The first array inside reference is 1, the second array is 2, and so on.

For example, in the formula below, area_num is supplied as 2, which refers to the range A7:C10:

=INDEX((A1:C5,A7:C10),1,3,2)

In the above formula, INDEX will return the value at row 1 and column 3 of A7:C10.

• Multiple ranges in reference are separated by commas and enclosed in parentheses.
• All ranges must on one sheet or INDEX will return a #VALUE error. Use the CHOOSE function as a workaround.

OFFSET is probably the function you want.

=OFFSET(A1:A4,1,,2)

But to answer your question, INDEX can indeed be used to return an array. Or rather, two INDEX functions with a colon between them:

=INDEX(A1:A4,2):INDEX(A1:A4,3)

This is because INDEX actually returns a cell reference OR a number, and Excel determines which of these you want depending on the context in which you are asking. If you put a colon in the middle of two INDEX functions, Excel says «Hey a colon…normally there is a cell reference on each side of one of these» and so interprets the INDEX as just that. You can read more on this at http://www.excelhero.com/blog/2011/03/the-imposing-index.html

I actually prefer INDEX to OFFSET because OFFSET is volatile, meaning it constantly recalculates at the drop of a hat, and then forces any formulas downstream of it to do the same. For more on this, read my post https://chandoo.org/wp/2014/03/03/handle-volatile-functions-like-they-are-dynamite/

You can actually use just one INDEX and return an array, but it’s complicated, and requires something called dereferencing. Here’s some content from a book I’m writing on this:

The worksheet in this screenshot has a named range called Data assigned to the range A2:E2 across the top. That range contains the numbers 10, 20, 30, 40, and 50. And it also has a named range called Elements assigned to the range A5:B5. That Elements range tells the formula in A8:B8 which of those five numbers from the Data range to display.

If you look at the formula in A8:B8, you’ll see that it’s an array-entered INDEX function: {=INDEX(Data,Elements)}. This formula says, “Go to the data range and fetch elements from it based on whatever elements the user has chosen in the Elements range.”
In this particular case, the user has requested the fifth and second items from it. And sure enough, that’s just what INDEX fetches into cells A8:B8: the corresponding values of 50 and 20.

But look at what happens if you take that perfectly good INDEX function and try to put a SUM around it, as shown in A11. You get an incorrect result: 50+20 does not equal 50. What happened to 20, Excel?

For some reason, while =INDEX(Data,Elements) will quite happily fetch disparate elements from somewhere and then return those numbers separately to a range, it is rather reluctant to comply if you ask it to instead give those numbers to another function. It’s so reluctant, in fact, that it passes only the first element to the function.

Consequently, you’re seemingly forced to return the results of the =INDEX(Data,Elements) function to the grid first if you want to do something else with it. Tedious. But pretty much every Excel pro would simply tell you that there’s no workaround…that’s just the way it is, and you have no other choice.

Buuuuuuuut, they’re wrong. At the post http://excelxor.com/2014/09/05/index-returning-an-array-of-values/, mysterious formula superhero XOR outlines two fairly simple ways to “de-reference” INDEX so that you can then use its results directly in other formulas; one of those methods is shown in A18 above. It turns out that if you amend the INDEX function slightly by adding an extra bit to encase that Elements argument, INDEX plays ball. And all you need to do is encase that Elements argument as I’ve done below:

N(IF({1},Elements))

With this in mind, your original misbehaving formula:

=SUM(INDEX(Data,Elements))

…becomes this complex but well-mannered darling:

=SUM(INDEX(Data, N(IF({1},Elements))))

Excel INDEX Function (Examples + Video)

When to use Excel INDEX Function

Excel INDEX function can be used when you want to fetch the value from a tabular data and you have the row number and column number of the data point. For example, in the example below, you can use the INDEX function to get the marks of ‘Tom’ in Physics when you know the row number and the column number in the data set.

What it Returns

It returns the value from a table for the specified row number and column number.

Syntax

=INDEX (array, row_num, [col_num])
=INDEX (array, row_num, [col_num], [area_num])

INDEX function has 2 syntax. The first one is used in most cases, however, in case of three-way lookups, the second one is used (covered in Example 5).

Input Arguments

• array – a range of cells or an array constant.
• row_num – the row number from which the value is to be fetched.
• [col_num] – the column number from which the value is to be fetched. Although this is an optional argument, but if row_num is not provided, it needs to be given.
• [area_num] – (Optional) If array argument is made up of multiple ranges, this number would be used to select the reference from all the ranges.

Additional Notes (Boring Stuff.. But Important to Know)

• If the row number or the column number is 0, it returns the values of the entire row or column respectively.
• If INDEX function is used in front of a cell reference (such as A1:) it returns a cell reference instead of a value (see examples below).
• Most widely used along with the MATCH function.
• Unlike VLOOKUP, INDEX function can return a value from the left of the lookup value.
• INDEX function have two forms – Array form and the Reference form
  • ‘Array form’ is where you fetch a value based on row and column number from a given table.
  • ‘Reference form’ is where there are multiple tables, and you use the area_num argument to select the table and then fetch a value within it using the row and column number (see live example below).

Excel INDEX Function – Examples

Here are six examples of using Excel INDEX Function.

Example 1 – Finding Tom’s Marks in Physics (a two-way lookup)

Suppose you have a dataset as shown below:

To find Tom’s marks in Physics, use the below formula:

=INDEX($B$3:$E$10,3,2)

This INDEX formula specifies the array as $B$3:$E$10 which has the marks for all the subjects. Then it uses the row number (3) and column number (2) to fetch Tom’s marks in Physics.

Example 2 – Making the LOOKUP Value Dynamic using MATCH Function

It may not always be possible to specify the row number and the column number manually. You may have a huge data set, or you may want to make it dynamic so that it automatically identifies the name and/or subject specified in cells and give the correct result.

Something as shown below:

This can be done using a combination of the INDEX and the MATCH function.

Here is the formula that will make the lookup values dynamic:

=INDEX($B$3:$E$10,MATCH($G$5,$A$3:$A$10,0),MATCH($H$4,$B$2:$E$2,0))

In the above formula, instead of hard-coding the row number and the column number, MATCH function is used to make it dynamic.

• Dynamic Row Number is given by the following part of the formula – MATCH($G$5,$A$3:$A$10,0). It scans the name of students and identifies the lookup value ($G$5 in this case). It then returns the row number of the lookup value in the dataset. For example, if the lookup value is Matt, it’ll return 1, if it is Bob, it’ll return 2 and so on.
• Dynamic Column Number is given by the following part of the formula – MATCH($H$4,$B$2:$E$2,0). It scans the subject names and identifies the lookup value ($H$4 in this case). It then returns the column number of the lookup value in the dataset. For example, if the lookup value is Math, it’ll return 1, if it is Physics, it’ll return 2 and so on.

Example 3 – Using Drop Down Lists as Lookup Values

In the above example, we have to manually enter the data. That could be time-consuming and error-prone, especially if you have a huge list of lookup values.

A good idea in such cases is to create a drop down list of the lookup values (in this case, it could be student names and subjects) and then simply choose from the list. Based on the selection, the formula would automatically update the result.

Something as shown below:

This makes a good dashboard component as you can have a huge data set with hundreds of students at the back end, but the end user (let’s say a teacher) can quickly get the marks of a student in a subject by simply making the selections from the drop down.

How to make this:

The formula used in this case is the same used in Example 2.

=INDEX($B$3:$E$10,MATCH($G$5,$A$3:$A$10,0),MATCH($H$4,$B$2:$E$2,0))

The lookup values have been converted into drop-down lists.

Here are the steps to create the Excel drop down list:

• Select the cell in which you want the drop-down list. In this example, in G4, we want the student names.
• Go to Data –> Data Tools –> Data Validation.
• In the Data Validation Dialogue box, within the settings tab, select List from the Allow drop-down.
• In the source, select $A$3:$A$10
• Click OK.

Now you’ll have the drop-down list in cell G5. Similarly, you can create one in H4 for the subjects.

Example 4 – Return Values from an Entire Row/Column

In the above examples, we’ve used Excel INDEX function to do a 2-way lookup and get a single value.

Now, what if you want to get all the marks of a student. This can enable you to find the maximum/minimum score of that student, or the total marks scored in all subjects.

In simple English, you want to first get the entire row of scores for a student (let’s say Bob) and then within those values identify the highest score or the total of all the scores.

Here is the trick.

In Excel INDEX Function, when you enter the column number as 0, it will return the values of that entire row.

So the formula for this would be:

=INDEX($B$3:$E$10,MATCH($G$5,$A$3:$A$10,0),0)

Now this formula. if used as is, would return the #VALUE! error. While it displays the error, in the backend, it returns an array that has all the scores for Tom – {57,77,91,91}.

If you select the formula in the edit mode and press F9, you’ll be able to see the array it returns (as shown below): 

Similarly, based on what the lookup value is, when the column number is specified as 0 (or is left blank), it returns all the values in the row for the lookup value

Now to calculate the total score obtained by Tom, we can simply use the above formula within the SUM function.

=SUM(INDEX($B$3:$E$10,MATCH($G$5,$A$3:$A$10,0),0))

On similar lines, to calculate the highest score, we can use MAX/LARGE and to calculate minimum, we can use MIN/SMALL.

Example 5 – Three Way Lookup Using INDEX/MATCH

Excel INDEX function is built to handle three-way lookups.

What is a three-way lookup?

In the above examples, we’ve used one table with scores for students in different subjects. This is an example of a two-way lookup as we use two variables to fetch the score (student’s name and the subject).

Now, suppose in a year, a student has three different levels of exams, Unit Test, Midterm, and Final Examination (that’s what I had when I was a student).

A three-way lookup would be the ability to get a student’s marks for a specified subject from the specified level of exam. This would make it a three-way lookup as there are three variables (student’s name, subject’s name, and the level of examination).

Here is an example of a three-way lookup:

In the example above, apart from selecting the student’s name and subject name, you can also select the level of exam. Based on the level of exam, it returns the matching value from one of the three tables.

Here is the formula used in cell H4:

=INDEX(($B$3:$E$7,$B$11:$E$15,$B$19:$E$23),MATCH($G$4,$A$3:$A$7,0),MATCH($H$3,$B$2:$E$2,0),IF($H$2="Unit Test",1,IF($H$2="Midterm",2,3)))

Let’s break down this formula to understand how it works.

This formula takes four arguments. INDEX is one of those functions in Excel that has more than one syntax.

=INDEX (array, row_num, [col_num])
=INDEX (array, row_num, [col_num], [area_num])

So far in all the example above, we have used the first syntax, but to do a three-way lookup, we need to use the second syntax.

Now let’s see each part of the formula based on the second syntax.

• array – ($B$3:$E$7,$B$11:$E$15,$B$19:$E$23): Instead of using a single array, in this case, we have used three arrays within parenthesis.
• row_num – MATCH($G$4,$A$3:$A$7,0): MATCH function is used to find the position of the student’s name in cell $G$4 in the list of student’s name.
• col_num – MATCH($H$3,$B$2:$E$2,0): MATCH function is used to find the position of the subject name in cell $H$3 in the list of subject’s name.
• [area_num] – IF($H$2=”Unit Test”,1,IF($H$2=”Midterm”,2,3)): The area number value tells the INDEX function which array to select. In this example, we have three arrays in the first argument. If you select Unit Test from the drop-down, the IF function returns 1 and the INDEX functions select 1st array from the three arrays (which is $B$3:$E$7).

Example 6 – Creating a Reference Using the INDEX Function (Dynamic Named Ranges)

This is one wild use of the Excel INDEX function.

Let’s take a simple example.

I have a list of names as shown below:

Now I can use a simple INDEX function to get the last name on the list.

Here is the formula:

=INDEX($A$2:$A$9,COUNTA($A$2:$A$9))

This function simply counts the number of cells that are not empty and returns the last item from this list (it works only when there are no blanks in the list).

Now, what here comes the magic.

If you put the formula in front of a cell reference, the formula would return a cell reference of the matching value (instead of the value itself).

=A2:INDEX($A$2:$A$9,COUNTA($A$2:$A$9))

You would expect the above formula to return =A2:”Josh” (where Josh is the last value in the list). However, it returns =A2:A9 and hence you get an array of names as shown below:

One practical example where this technique can be helpful is in creating dynamic named ranges.

That’s it in this tutorial. I’ve tried to cover major examples of using the Excel INDEX function. If you would like to see more examples added to this list, let me know in the comments section.

Note: I’ve tried my best to proof read this tutorial, but in case you find any errors or spelling mistakes, please let me know 🙂

Excel INDEX Function – Video Tutorial

Related Excel Functions:

• Excel VLOOKUP Function.
• Excel HLOOKUP Function.
• Excel INDIRECT Function.
• Excel MATCH Function.
• Excel OFFSET Function.

You May Also Like the Following Excel Tutorials:

• VLOOKUP Vs. INDEX/MATCH
• Excel Index Match
• Lookup and Return Values in an Entire Row/Column.

‘INDEX‘ function examples

The following 237 articles contain the INDEX function.

Functions in this article

Functions in ‘Lookup and reference’ category

The INDEX function function is one of many functions in the ‘Lookup and reference’ category.

Excel function categories

Excel categories

In this article, we will learn How to use the INDEX function in Excel.

Why do we use the INDEX function ?

Given a table of 500 rows and 50 columns and we need to get a value at 455th row and 26th column. For this either we can scroll down to the 455th row and traverse to the 26th column and copy the value. But we can’t treat Excel like hard copies. Index function returns the value at a given row and column index in a table array. Let’s learn the INDEX function Syntax and illustrate how to use the function in Excel below.

INDEX Function in Excel

Index function returns the cell value at matching row and column index in array.

Syntax:

=INDEX(array, row number, [optional column number])

array : It is the range or an array.

row number : Ther row number in your array from which you want to get your value.

column number : [optional] This column number in array. It is optional. If omitted INDEX formula automatically takes 1 as default.

Excel’s INDEX function has two forms known as:

• Array Form INDEX Function
• Reference Form INDEX Function

Example :

All of these might be confusing to understand. Let’s understand how to use the function using an example. Here we have this data.

I want to retrieve data at the intersection of 3rd Row and 2nd Column. I write this INDEX formula in cell H2:

The result is Gill:

Reference Form INDEX Function

It is much like a multidimensional array index function. Actually in this form of INDEX function, we can give multiple arrays and then in the end we can tell the index from which array to pull data.

Excel INDEX Function Reference Form Syntax

=INDEX( (array1, array2,…), row number,  [optional column number],  [optional array number] )

(array1, array2,…) : This parenthesis contains a list of arrays. For example (A1:A10,D1:R100,…).

Row number : Ther row number in your array from which you want to get your value.

[optional column number] : This column number in array. It is optional. If omitted, the INDEX formula automatically takes 1 for it.

[optional array number] : The area number from which you want to pull data. In excel it is shown as area_num

Come, let’s have an example.

I have these 3 tables in Excel Worksheet.

Area 1, Area 2 and Area 3 are my ranges as shown in the above image. I need to retrieve data according to values in cell L2, L3 and L4. So, I write this INDEX formula in cell M1.

=INDEX(($B$3:$C$7,$E$3:$F$7,$H$3:$I$7),L2,L3,L4)

Here L2 is 1, L3 is 2 and L4 is 1. Hence the INDEX function will return the value from the 1st row of the second column from the 1st array. And that is East.

Now change L2 to 2 and L4 to 2. You will have West in M2, as shown in below image.

And so on.

The INDEX function in Excel is mostly used with MATCH Function. The INDEX MATCH function is so famous that it is sometimes thought of as one single function. Here I have explained the INDEX MATCH function with multiple criteria in detail. Go check it out. How to lookup values using the INDEX and MATCH function

Hope this article about How to use the INDEX function in Excel is explanatory. Find more articles on calculating values and related Excel formulas here. If you liked our blogs, share it with your friends on Facebook. And also you can follow us on Twitter and Facebook. We would love to hear from you, do let us know how we can improve, complement or innovate our work and make it better for you. Write to us at info@exceltip.com.

Related Articles :

Use INDEX and MATCH to Lookup Value : The INDEX & MATCH formula is used to lookup dynamically and precisely a value in a given table. This is an alternative to the VLOOKUP function and it overcomes the shortcomings of the VLOOKUP function.

Use VLOOKUP from Two or More Lookup Tables : To lookup from multiple tables we can take an IFERROR approach. To lookup from multiple tables, it takes the error as a switch for the next table. Another method can be an If approach.

How to do Case Sensitive Lookup in Excel : The excel’s VLOOKUP function isn’t case sensitive and it will return the first matched value from the list. INDEX-MATCH is no exception but it can be modified to make it case sensitive.

Lookup Frequently Appearing Text with Criteria in Excel : The lookup most frequently appears in text in a range we use the INDEX-MATCH with MODE function.

Popular Articles :

How to use the IF Function in Excel : The IF statement in Excel checks the condition and returns a specific value if the condition is TRUE or returns another specific value if FALSE.

How to use the VLOOKUP Function in Excel : This is one of the most used and popular functions of excel that is used to lookup value from different ranges and sheets.

How to use the SUMIF Function in Excel : This is another dashboard essential function. This helps you sum up values on specific conditions.

How to use the COUNTIF Function in Excel : Count values with conditions using this amazing function. You don’t need to filter your data to count specific values. Countif function is essential to prepare your dashboard.