7 reasons why you should get cozy with INDEX()
Today lets get cozy. Lets start a fling (a very long one). Lets do something that will make you smart, happy and relaxed.
Don’t get any naughty ideas. I am talking about INDEX() formula.
INDEX?!?
Of all the hundreds of formulas & thousands of features in Excel, INDEX() would rank somewhere in the top 5 for me. It is a versatile, powerful, simple & smart formula. Although it looks plain, it can make huge changes to the way you analyze data, calculate numbers and present them. It is so important that, whenever I teach (live or online), I usually dedicate 25% of teaching time to INDEX().
Enough build up. Lets get cozy with INDEX.
Understanding INDEX formula
In simple terms, INDEX formula gives us value or the reference to a value from within a table or range.
While this may sound trivial, once you realize what INDEX can do, you would be madly in love with it.
Few sample uses of INDEX
1. Lets say you are the star fleet commander of planet zorg. And you are looking at a list of your fleet in Excel (even in other planets they use Excel to manage data). And you want to get the name of 8th item in the list.
INDEX to rescue. Write =INDEX(list, 8)
2. Now, you want to know the captain of this 8th ship, which is in 3rd column. You guessed right, again we can use INDEX,
=INDEX(list, 8,3)
Syntax of INDEX formula
INDEX has 2 syntaxes.
1. INDEX(range or table, row number, column number)
This will give you the value or reference from given range at given row & column numbers.
2. INDEX(range, row number, column number, area number)
This will give you the value or reference from specified area at given row & column numbers.
It may be difficult to understand how these work from the syntax definition. Read on and everything will be clear.
7 reasons why INDEX is an awesome companion
Whether you are in planet zorg managing dozens of star fleet or you are in planet earth managing a list of vendors, chances are you are wrestling everyday with data, pleasing a handful of managers (and clients), delivering like a rock star all while having fun. That is why you should partner with INDEX. It can make you look smart, resourceful and fast, without compromising your existing relationship with another human being.
Data used in these examples
For all these examples (except #6), we will use below data. It is in the table named sf.
Reason 1: Get nth item from a list
You already saw this in action. INDEX formula is great for getting nth item from a list of values. You simply write =INDEX(list, n)
Reason 2: Get the value at intersection of given row & column
Again, you saw this example. INDEX formula can take a table (or range) and give you the value at nth row, mth column. Like this =INDEX(table, n, m)
Reason 3: Get entire row or column from a table
For some reason you want to have the entire or column from a table. A good example is you are analyzing star fleet ages and you want to calculate average age of all ships.
You can write =AVERAGE(age column)
or you can also use INDEX to generate the age column for you. Assuming the fleet table is named sf and age is in column 7
write =AVERAGE(INDEX(sf, ,7))
Notice empty value for ROW number. When you pass empty or 0 value to either row or column, INDEX will return entire row or column.
Likewise, if you want an entire row, you can pass either empty or 0 value for column parameter.
Reason 4: Use it to lookup left
By now you know that VLOOKUP() cannot fetch values from columns to left. It does not matter if the person looking up is the star fleet commander.
But INDEX along with MATCH can fix this problem.
Lets say you want to know which ship has maximum capacity.
 First you find what is the maximum capacity =MAX(sf[Capacity (000s tons)])
 Then you find position of of this capacity in all values =MATCH(max_capacity, sf[Capacity (000s tons)],0)
 Now, extract the corresponding ship name =INDEX(sf[Ship Name], max_capacity_position)
Or in one line, the formula becomes
=INDEX(sf[Ship Name], MATCH( MAX(sf[Capacity (000s tons)]), sf[Capacity (000s tons)], 0))
For more tips read using INDEX + MATCH combination
Reason 5: Create dynamic ranges
So far, your reaction to INDEX’s prowess might be ‘meh!’. And that is understandable. You are of course star fleet commander and it is difficult to please you. But don’t breakup with INDEX yet.
You see, the true power of INDEX lies in its nature. While you may think INDEX is returning a value, the reality is, INDEX returns a reference to the cell containing value.
So this means, a formula like =INDEX(list, 8) looks like it is giving 8th value in list.
But it is really giving a reference to 8th cell.
Since the result of INDEX is a reference, we can use INDEX in any place where we need to have a reference.
Sounds confusing?
For example, to sum up a list of values in range A1:A10, we write =SUM(A1:A10)
Now, in that formula, both A1 and A10 are references.
Since INDEX gives a reference, we can replace either (or both) A1 & A10 with INDEX formula and it still works.
so =SUM(A1 : INDEX(A1:A50,10))
will give the same result as =SUM(A1:A10)
Although the INDEX route appears overly complicated, it has other applications.
Example 1: SUM of staff in first x ships
Lets say you want to sum up staff in first ‘x’ ships in the sf table.
Since ‘x’ changes from time to time, you want a dynamic range that starts from first ship and goes up to xth ship.
Assuming ‘x’ value is in cell M1 and first ship’s staff is in cell G3,
=SUM(G3:INDEX(sf[Staff count], M1))
will give the desired result.
Example 2: A named range that refers to all ship names in column A
Many times you do not know how much data you have. Even star fleet commanders are left in dark. Lets say you are building a new ship tracking spreadsheet. Since your fleet is ever growing, you do not want to constantly update all formulas to refer to correct ranges.
For example, the ship names are in column A, from A1 to An. And you want to create a named range that points to all ships so that you can use this name elsewhere.
If you define the lstShips =A1:A10, then after you add 11th ship, you must edit this name. And you hate repetitive work.
One solution is to use OFFSET formula to define the dynamic range,
like =OFFSET(A1, 0,0, COUNTA(A:A),1)
While this works ok, since OFFSET is volatile function, it will recalculate every time something changes in your workbook. Even when someone replaces a bolt on landing gear of USS Enterprise.
This will eventually make your workbook slow.
That is where INDEX comes.
You see, INDEX is a nonvolatile function*.
So you can create lstShips that points to,
=A1: INDEX(A:A, COUNTA(A:A))
*Even though INDEX is nonvolatile, since we are using it in defining a range reference, Excel recalculates the lstShips every time you open the file. (reference).
Reason 6: Get any 1 range from a list of ranges
INDEX has another powerful use. You can get any one range from many ranges using INDEX.
Since you are a successful, smart & resourceful star fleet commander, you got promoted. Now you manage fleet of several planets.
And you have similar ship detail tables for each planet in a workbook. And you want to calculate average age of any planet’s ships with just one formula.
Again INDEX to rescue.
Assuming you have 3 different tables – planet1, planet2, planet3
and selected planet number is in cell C1,
write =AVERAGE(INDEX((planet1,planet2,planet3),,,C1))
The reference (planet1,planet2,planet3) will point to all data and C1 will tell INDEX which planet’s data to use.
Pretty nifty eh?!?
Reason 7: INDEX can process arrays
INDEX can naturally process arrays of data (without entering CTRL+Shift+Enter).
For example you want to find out how much staff is in the ships whose captain’s name starts with “R”.
write =SUM(INDEX((LEFT(sf[Captain],1)=“r”)*(sf[Staff count]),0))
Although LEFT(sf[Captain],1)=”r” and sf[Staff count] produce arrays, since INDEX can process arrays automatically, the result comes without CTRL+Shift+Enter
Where as if you use SUM alone =SUM((LEFT(sf[Captain],1)=”r”)*(sf[Staff count])) you have to press CTRL+Shift+Enter to get correct results.
Other formulas: SUMPRODUCT & MATCH too can process arrays automatically.
Download Example Workbook & Get close with INDEX
Since you are going to ask, “I want to spend sometime alone with INDEX in my cubicle right now!”, I made an example workbook. It explains all these powerful uses of INDEX. Go ahead and download it.
Get busy with INDEX.
Why do you love INDEX?
I love INDEX(). If we get a dog, I am going to call her INDEX. That is how much I love the formula. Almost all my dashboards, complex workbooks and anything that seems magical will have a fair dose of INDEX formulas.
What about you? Do you use INDEX formula often? What are the reasons you love it? Please share your tips, usages and ideas on INDEX using comments.
Learn more about INDEX & other such lovely things in Excel
If you are whistling uncontrollably after reading so far, you are in for a real treat. Check out below articles to become awesome.
 The Imposing INDEX function – a good overview of how INDEX behaves
 INDEX + MATCH Combination
 Introduction to SUMIFS formula
 More examples of advanced Excel formulas & INDEX
 
 

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Using Arrays To Update Table Columns  How to Solve an Equation in Excel 
46 Responses to “7 reasons why you should get cozy with INDEX()”
Reason 7 it says ‘ships whose captain’s name starts with “S”’ but then the formula has ‘LEFT(sf[Captain],1)=”r”’
Thanks JD for pointing this out. Fixed it now
Because it save me every time
For some reason I cannot download your file. It shows that format or data is corrupted.
Would you please repost it?
Thank you,
Dan
Can you try again.. I can download and open the file alright. Also make sure you save the file before opening it in Excel.
Hi,
still I cannot download your Excel example. Would you please save it in Excel 2003? Thank you.
@Kazdima
Just emailed to you
Hui…
Reason 4: Use it to lookup left
By now you know that VLOOKUP() cannot fetch values from columns to left.
What, It can’t?
Excel can lookup to the left and you can read about it right here:
http://chandoo.org/wp/2012/09/06/formulaforensicsno028/
Now that would make INDEX look less sexy
But you are right…
BUT Vlookup & Hlookup are much less auditable because you need to go and count so many columns (lines) within certain area, while for most lookups with INDEX&MATCH you can directly see the area it pulls the data from.
Maybe exception would be 2Dlookups, but then Vlookup wouldn’t do the trick at all.
Get two dogs and call the second one “Match”!
What would be the advantage of using offset over index? They seem to be interchangeable functions and index seems to always be better. I use index constantly and can never think of a situation I would use offset over index.
just curious if you had any thoughts….thanks
I agree. Once you are very comfortable with INDEX, there is little incentive to go back to OFFSET.
Offset gives the flexibility of the starting position of the dynamic range… not sure how INDEX can achieve it??
Two indexes one for the start ref and one the end ref. Separated by colon.
=SUM(INDEX(A:A,5):INDEX(A:A,10))
Sums A5 to A10
The values 5 and 10 could be replaced by cell refs to provide flexibility.
Hi Neale,
Thanks for that formula. It works fine. However the formula will look really long and “complicated” if i further to change the hardcode number to cell refs…
In this sense, I think OFFSET is a not bad alternative.
In INDEX example 7 on the spreadsheet, the displayed formulas in N25:N26 show a cell reference for L23; it should be L24 (the letter “r”) for both instances. Interesting column!
Hi Jim,
Fixed this. I have added a row after creating the file. Hence the mistake.
I use it for left lookup only.But after reading this post…seems I should try others too.
I am nothing without the INDEX formula.
I have a workbook that has a bunch of tables in it being crossreferenced every which way. Since the row I want is determined dynamically, I started using Index() with Match(). For my purposes the columns had to be be sorted alphabetically by header, and I knew that more columns would need to be added over time, which would break any formula where you specified a column number. Then I realized I just needed another match formula in there where I specify which header I’m looking for and the formula figures out which column number that is currently. Better than aspirin for curing that headache, and it wouldn’t have been possible without Index() or Match().
You said it right. See 2 way lookup formulas for similar examples and additional techniques.
http://chandoo.org/wp/2010/11/09/2waylookupformulas/
I am in love with INDEX Formula because of reason # 7 and Reason # 5. I like it so much.
Thanks Chandoo
In the sample sheet,
#1 ship name & #2 captain name:
it would have been nicer if you had formatted the example more like #5 so that the formula refers to a cell and we can change the number to see the result change.
Actually, I defined a highlighted cell for “Input Position” at the top of the examples and pointed both #1 and #2 at it.
#5 your text of the formula says “M17″, it should be “M18″ as it is in the actual formula
It would be nice if you stated up front that the “sf” used in the formulas is a name for the table range B4:H23. Better still, make the name more descriptive than “sf”, ie “ship_info_tbl”
I am curious, what did you do in column N to display the formulas as text rather than results
I am curious, what did you do in column N to display the formulas as text rather than results
try this
‘=AVERAGE(INDEX(sf,,7))
You can format the cell containing a formula as Text (Format Cells) and then press F2 and press Enter which will then show the formula as text and it will not calculate.
Excel 2013 has a FORMULATEXT function that does it via a function.
PS: How did you place the links inside of the “Learn More” text box. They seem to be placed in column N, I just can’t figure out how.
Thanks for the good example sheet.
I have a special version of Excel where I can create cells on top of other cells.
Just kidding.
All of these are text boxes, neatly arranged together.
I really love INDEX too. Looks like we’re gonna have to fight to keep that girl named INDEX. She is mine.
I really love the array use of it.
Great tips. Thanks so much.
Thanks for the post Chandoo.
Yes, INDEX is a very versatile function.
In reason 5 Example 2 if you already have table names defined you can use =sf[Ship name] to define lstShips as this avoids the volatile issue.
I have used the INDEX version for dynamic names but am switching more and more to the table names for single column lists that need to be dynamic.
In Example 6 I’d probably use the CHOOSE function – which is also involved in Hui’s link above for a solution to the left hand side VLOOKUP.
I agree with you. It has been a while since I used INDEX to create a dynamic reference. I rely on tables for most of such needs.
Here is a link to Daniel Ferry’s blog on INDEX – he loves INDEX too.
http://www.excelhero.com/blog/2011/03/theimposingindex.html
This was required reading for his Excel Hero Academy students – hence there are lots of comments.
@Neale
That link is already in Chandoo’s list of links above.
Apologies @Hui – missed that on the scroll down.
Good to know about INDEX. i will start using it in my class data records.
Just spent the day learning OFFSET, looks like tomorrow I will be working on INDEX, thanks for the post.
I love to use Index in charts so that they update automatically as dynamic ranges. It is a great time saver.
I have a question about how the reason number 6 syntax works. When it’s selecting the “3″(C1) in the function is it grabbing the 3rd table that is mentioned in the index formula? So if I had my selections out of order in the equation, it wouldn’t be effective?
Also I may have told a date in the past that I did love the INDEX function. Excitedly, while we were enjoying some super fancy five dollar pizza, I was attempting to explain how it had simplified a problem at work. When it became obvious he had lost track of the conversation I quickly summed it up with “I just love the INDEX function ok?”
Index function is very helpfull for dynamic chart as well for lookup data in table that i have able to used learning through chandoo.org. thanks
chandoo
Your site is awesome. Not only is it great Excel, it’s a lot of fun to read
Finally, I have a better understanding of the 2nd syntax of INDEX through example #6. Thanks!!
[…] 7 reasons why you should get cozy with INDEX() […]
Thanks for sharing your knowledge.
A quick question, when I input this it give me an error. Little bit confused whether to write it this way
MAX(sf[Capacity (000s tons)])
or input
MAx(sf , E7(where the capacity is entered)
Any help will be appreciated.
This site never fails to excite me! Thanks for the lessons Chandoo! Waahooo!
I am trying to figure out how to do something and after reading this I think Index will be heavily involved, but I’ve never used it so I’m not sure how to accomplish this. Let’s take example 6 above and say we have multiple ships the same age across all 3 planets. Say I wanted to create a new list that listed all of the Ship Names that are 66, then 67, then 68, then 69 (i need 4 values in my situation). I am racking my brain for all of the formulas I know and I cannot get this.
[…] INDEX formula – introduction, how to use it and why you should use it? […]