Excel formulas acting slow? Today lets talk about optimizing & speeding up Excel formulas. Use these tips & ideas to super-charge your sluggish workbook. Use the best practices & formula guidelines described in this post to optimize your complex worksheet models & make them faster.
10 Tips to Optimize & Speed up Excel Formulas
1. Use tables to hold the data
Starting Excel 2007 you can keep all the related data in a table. For example call center data in our recent dashboard is kept in a table. Tables can be used in formulas with structural references, can be used as a source for pivot tables etc. And since tables grow & shrink as you add / remove data, none of your formulas need to be dynamic. As an example, if you have table called cs, then the formula sum(cs[column_name]) refers to sum of all values in the column_name of table cs. Even if you add more data to CS, the formula still works.
Resources to learn about Excel Tables:
- Introduction to Excel Tables – what are they and how to use them?
- Example: Customer Service Dashboard – Data & Calculations
2. Use named ranges, named formulas
By using names and named formulas, you can simplify your spreadsheet. Not only that, since named ranges & named formulas can hold arrays (ie lists of values), you can hold intermediate results or values that you need to refer many times in these named formulas. This will reduce the formula overhead and makes your workbooks faster.
Resources to learn about named ranges & named formulas:
- Excel School Program: In this comprehensive course, I talk about how to think about and write better formulas for data analysis work.
- Musings on Live Calendar [Excel Hero]
- Examples of Named Formulas – 2023 Calendar in Excel
3. Use Dynamic Arrays & Spill Ranges
Introduced in Excel 365, Dynamic Arrays allow us to build complex calculations with ease. I suggest incorporating new functions like:
- FILTER to fetch a list of values that meet one or more criteria.
- SORT to sort the values
- UNIQUE to eliminate duplicate values on the fly
- XLOOKUP to perform various lookups
- VSTACK / HSTACK to combine datasets
- TOCOL / TOROW to convert tables of data to single row or column formats
- # or Spill operator to manage spill ranges
Learn more about Dynamic Array functions here:
- Dynamic Array Functions – A deep introduction
- Dynamic Array Functions – how to use them [Video]
- How to use XLOOKUP
4. Use Pivot Tables
Many times, even when we do not need formulas we use them, because we can. Pivot tables are an excellent way to calculate a lot of summary values with few clicks. Once the pivot is built, you can refer to the pivot values with GETPIVOTDATA or simple cell references. This will reduce a lot of unnecessary calculations. If you are changing the data, you can just go to DATA ribbon and refresh all pivots in one go. This process works smoothly when you use tables to hold the data.
One of the reasons for slow workbooks is lot of data. Since, pivot tables are designed to work with lots of data, by using them, you can speed up your workbooks.
Resources to learn Pivot Tables:
5. Sort your data
One of the reasons for sluggish performance is that you are searching for something in a lot of un-sorted data. You are making Excel look for a needle in a hay-stack. Many times we inherit un-sorted data thru data imports. By sorting the data & using correct operators in lookup formulas, we can instantly speedup a sluggish workbook. If you feel that sorting the data is a pain, you can even automate it with Power Query or a sort procedure (thru a simple VBA macro).
Examples on Sorting:
- Remove duplicates & sort a list using Pivot Tables
- Use Power Query to pre-sort the data you are working with
6. Use Manual Calculation Mode
Speed is the hefty price you pay for complexity. But many times, we want our Excel workbooks to be complex, because only then they would reflect real world. In such cases, you can set formula calculations to manual mode.
Just press F9 whenever you want to run the formulas. Please note that Excel runs formulas whenever you save the file too.
7. Use Non-volatile formulas
There are a class of formulas in excel called as volatile formulas. These formulas are re-calculated whenever there is a change in the workbook. Examples of volatile formulas are RAND, NOW, TODAY, OFFSET etc. So when your worksheet has a lot of volatile formulas, any time you make a change all these formulas must be re-calculated. Thus, your worksheet becomes slow.
Solution? Simple, do not use volatile formulas. For example, instead of using OFFSET to construct a dynamic range, you can use INDEX. Since INDEX is non-volatile, it tends to be faster. Or better still, use a table.
Resources to learn more:
8. Keep formulas in a separate sheet
Formulas are the driving force behind any Excel workbook or model. By keeping all them in a separate worksheet(s), you minimize the chance of mistakes, omissions or repetitions. Debugging or investigating slow performance becomes an easy task when all formulas are in same place. I usually keep all the formulas in one sheet whenever I am designing a dashboard or complex workbook. This structure also helps me in thinking thru various calculations and planning the formulas in a structured way.
9. Write better formulas
Here are some guidelines that I follow when writing formulas.
- Built-in formulas tend to better than your own version – for example SUMIFS is easier to write and just as fast as SUMPRODUCT.
- Do not refer to entire column when you need just a few values. Do not write SUM(A:A), when you know values are only in A1:A10.
- IFERROR instead of lengthy IF(ISERROR formulas. Use IFERROR to simplify your error checking.
- Remove or Fix formula errors [how to, findout why formulas are not working]
- Use newer Dynamic Array formulas instead of old clunky array formulas
- Remove or Reduce references to other workbooks. Use Power Query instead.
- Remove any named ranges that result in error or missing links.
- Try to come up with alternative formulas: this not only sharpens your mind, but lets you discover better solutions.
- Do not calculate something if you do not need it.
- Do not calculate same thing twice. Use the first result second time too. Use LET for accomplishing this.
Resources to write better formulas:
- Introduction to SUMIFS formula
- Introduction to XLOOKUP formula
- How to use the new Dynamic Array functions in Excel
- Introduction to SUMPRODUCT formula
- Introduction to IFERROR formula
- Excel Formula Forensics
- Excel School program
10. Desperate times need desperate measures
Sometimes, no matter what you do, the workbook remains slow. Here are a few whacky ideas that I try in such cases:
- Replace formulas with values. I take a backup of the formulas. Then I select everything, CTRL+C, ALT+ESV (or CTRL Shift V). Done!
- Develop the workbook from scratch: Sometimes it helps to design the workbook afresh.
- Replace external data links with actual data: And import data by copy-pasting if needed.
- Reduce the functionality: See if the end user can live with fewer features in the workbook.
- Find an alternative solution: Trying to do everything in Excel is foolish. See if there is any external tool that can do this better & faster.
BONUS: Learn new formulas & play with them
Optimization is not a one-shot exercise. It is an ongoing-business. So you need to constantly learn new formulas, new uses & play with them. This way, you see new ways to improve a sluggish workbook. To begin with, explore our Formula homework & formula forensics pages and see how you solve these problems.
How do you speed-up your Excel formulas?
So how do you optimize & speed-up your Excel formulas? What techniques do you use? Please share using comments.
54 Responses
Hi Chandoo,
This is awesome *****
Found 6, just one remaining, and I think it should be in sheet2, as I found 1 in each sheet but didn’t found anything in sheet2 (till yet, I am keep looking).
Very cleaver and amazing work, enjoyed a lot…
Thanks Chandoo for this beautiful work.
Wish you have great time at Hyderabad.
Regards,
Khalid
go to AB201 on Sheet2, you will see Panda there !!!
Press F2 in Cell A1 and then read the actual text !!
In Sheet 2 go to Cell AB201. You will find one.
There is one on first sheet, if you press F5 (goto), the word PANDA can be seen there.
Oh I found the last one, (custom format hmm)
Truly Amazing and the beauty of this forum.
You are an Artist Chandoo.
Hi Chandoo,
Wow, you really have magical skills. I am in office and this sheet ate up an hour of my time….didn’t expect that.
I could find 5 of the 7 pandas. Didn’t know one could hide so much data in innocent looking excel sheets.
Thanks!
-Ranjith
yeah! found all 7 panda, time to go to china.
This was very fun and challenging, thanks for posting! I found all of them (well, Sheet1 was tricky, it seems you’re supposed to find the cell and type it in yourself?). Wasn’t sure if it was cool to post the answers here or not, though. Guess I’ll post SPOILER ALERTS so you can skip the rest of the message if you don’t want to see what I came up with.
SPOILER! SPOILER! SPOILER!
My answers appear below.
Sheet1: type PANDA in cell PAN3489
Sheet2: cell AB201
Sheet3: cell J8 (Picture1)
Sheet4: cell H9
Sheet5: expand Chart1
Sheet6: formula = “=MID(ADDRESS(9,2^3*23*59,4),1,3)&BIN2HEX(11011010)”
Sheet7: named range (A1:I18)
Wookie – I would love to get a walkthrough of HOW you figured out sheet 1 and a bit of a formula walkthrough for Sheet 6.
Basically, I don’t know how I could have found that particular cell input message on Sheet 1.
And I have no clue about the BIN2HEX part of the formula…before your hint I was able to get the output to read AN9DA. The change to MID and the addition of that ‘,1’ changed it to PANDA…
Hi Rachel,
To get to the cell in sheet 1 you can press: ctrl G. Then special and then data validation: all. This is also the way to find panda in sheet 7 😉
I agree, this was a fun way to test your ability to navigate through the functionality of Excel! And since you already posted the SPOILER ALERT warning, I should be safe posting a reply to your comment with some solutions of my own… 🙂
I found all the same solutions you did with a few minor changes:
Sheet1: If you notice, cell PAN3489 has Custom formatting. You don’t have to type “PANDA”, just the number 1.
Sheet6: The MID function works as you described, but you can also simply change the RIGHT function to the LEFT function without having to add in the start and end positions for MID.
Sheet7: Yes, the range name for these cells is called PANDA, but you don’t see the actual word in the sheet unless you change the Zoom setting to 39% or less (hence the clue “Z” 39%).
Thanks again for a great post, Chandoo!!
I must admit sheet 7 defeated me, but I have some corrections
Sheet 1 – you type =LEFT(ADDRESS(ROW(),COLUMN(),2),3)&DEC2HEX(ROW())
in PAN3489 to get “PANDA1”. As it is the first panda. I think panda1 is appropriate, but maybe
=LEFT(ADDRESS(ROW(),COLUMN(),2),3)&LEFT(DEC2HEX(ROW()),2)
is better, because it leaves you with “PANDA”
Sheet 6 – I corrected to
=LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
Picky I know, but who uses mid when a right or a left will do?
I know; that was weird. I did try using a LEFT formula, but I kept getting the $ prefix from the cell address. So I tried a couple of variations using MID and it gave me the result I needed. This is actually the first time I’ve ever tried using a MID formula starting at the first character, but I wasn’t trying to spend a lot of time on it, so I went with what worked.
Sheet1: Type 1 in PAN3489
Sheet6: =LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
Slight change…
For sheet 1 goto PAN3489 and type in 1. The word PANDA appears.
Love it!
Sheet 6 was my favorite. How many people still know what binary, hex and octal are? :o)
—–Spoilers———
Alternate Solutions
1) Type “1” (not the quotes) in PAN3489 and Excel will turn “1” into “PANDA”
6) The formula Wookie lists also works with LEFT in place of MID
Lot of fun. Solve time ~20 mins.
@ Rob
How this 1 turns to PANDA .. means How this is done by excel any formula or something in VBA
Also how to reach cell PAN3489 .. there are no clues given on sheet 1
You reach PAN3489 by pressing Ctrl + End to bring you to the last used cell in Sheet 1
@ Navdeep I found PAN3489 by going to “Formulas” and then “Name Manager” and saw there was a field called “Clue1” listed in the Name Manger that references 3489. Finding PAN as the column index was just a bit of a lucky guess through trial and error. Then a note in cell PAN3489 when you navigate there says to try “typing something.” I tried scrolling through the Format Cells menu to see if the text typed in the cell needed to be formatted a certain way, and noticed that “1= Panda” was listed in the custom text menu and tried it. A bit brute force, but I think the desired text entry.
Clever!
The Data Validation one took me a bit. Had to resort to brute force.
Thanks for the fun!
Awesome! Found 7 pandas in 20 minutes)))
Sheets 1 and 6 were the best!
Thanks!
Sheet 1: The answer is not type in Panda. Type 1. There’s a special formatting that replaces 1 with Panda.
Sheet 6: Just replace right with left, don’t worry about changing the numbers.
Sheet 7: I found the named range, but don’t know what the Z 39% means. Thoughts?
when you changed the zoom level to 39% or below, you will see the name of namedrange (if any)
WOW! I’ve just found the secret eighth PANDA!
Truly awesome!!!
Am I the first one who figured that out, guys?
Btw, thanks for the puzzle!
Found them all – very inventive. Had to think outside the “box”. Great fun!
It was truly a artists work
chandoo you are grate
all sheets are deigned different from each other
@Wookiee: you have a good for others by posting the answers, Thank you too
it is fun and great invent
Guys I Got 8 PANDA in the workbook… 🙂
[Look Chandoo has against played great trick by reserving one more ester egg, but we are also fan of none other than Chandoo, who can get hold of hidden 8th (untold) ester egg]
Here is the full list:
1) Sheet1: Type 1 in Cell PAN3489
2) Sheet2: Goto Cell AB201
3) Sheet3: Check the picture located above cell J8
4) Sheet4: Goto Cell H8
5) Sheet5: Cells, viz., A4, A10, A16, A21, A29 have all alphabets of PANDA
6) Sheet5: Resize the chart to see PANDA
7) Sheet6: Correct the formula as LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
8) Sheet7: Range A1:I18 is named as PANDA
1) Sheet1: Type 1 in Cell PAN3489
2) Sheet2: Goto Cell AB201
3) Sheet3: Check the picture in the cell J8
4) Sheet4: Goto Cell H9
5) Sheet5: Resize the chart to see PANDA
6) Sheet6: Correct the formula as LEFT(ADDRESS(9,2^3*23*59,4),3)&BIN2HEX(11011010)
7) Sheet7: Range A1:I18 is named as PANDA
Actually, for sheet7, if you set the zoom to 39% or less, you will see the word PANDA. Yet another PANDA! 🙂
Hi,
i want to know how to manage bill wise manage vendor invoice and payment in excel please suggest.
Thanks,
Ram
Hi Chandoo!
You rock with these amazing skills!
Sheet 1: ??
Sheet 2: ??
Sheet 3: Cell J8
Sheet 4: Cell H9
Sheet 5: A4, A10, A16, A21, A29
Sheet 6: B2
Sheet 7: ???
Sheet1 F5
Sheet2 AB201
Sheet3 Picture1
Sheet4 H9
Sheet5 Chart
Sheet7 Zoom to 30%
I love this time of year and look forward to Chandoo’s egg hunts. Whilst I got all the pandas, I do not understand how sheet 7 works; Where is the source data and why does it only work when zoomed out to 39% or more?
@Leon-K
When you change the zoom level to be less than 40% Excel shows the Ranges which have Names applied to them
Ha ha, that’s fantastic. Thanks Hui. @Chandoo, thanks for yet another method to decrypt worksheets in order to re-build or explain them better to clients.
These were fantastic and kept me intrigued until I could finish them. (Had to look here for help with Sheet1!) Definitely learning a lot about some new formulas. Awesome, Chandoo!
Ok, just saw the notes on the Zoom 39% on Sheet 7. Can someone explain what’s happening here and why PANDA shows up at that level?
@Bryan
When you change the zoom level to be less than 40% Excel shows the Ranges which have Names applied to them
Wow, great exercise.
Tried and solved 5 out of seven and other two solved incorrectly (1 & 6).
Thanks 🙂
Hi Chandoo,
Gr8 …had fun in searching it. I got 5 out of 7.
You are brilliant.
Found all except in sheet6 as not able to understand formula.
thanks
Raja Aurongzeb
Hi,
I am not able to find 1st Panda, which is on Sheet1. Rest all I have found.
Wonderful Chandooji… you are brilliant.
Wow.. Awesome set of puzzles Chandoo!!
Am now trying to figure out how sheet 7 was prepared.. 39% Zoom setting logic.. Can someone help me with a hint?
Thanks!
Looks like this is an XL feature.. Zooming out the worksheets below 40% level, by default displays all named ranges (more than 2 cells)! Had not come across this till date..
Great works! Was having FUN in finding the pandas. Thanks.
btw, I used one basic function (Find, CTRL+F) to find 2 pandas. Simply Find “Panda” within “Workbook”… To my surprise, seems no one mentioned that in the process.
On other other hand, Selection and Visibility Pane is a handy tool to see if there is “extra” shapes for locating pandas hidden in chart/picture.
Had fun doing this, Found 5 and the rest I saw clues on here 🙂
I really enjoyed when finding the pandas.And also I am so surprised.Very Nice thought and Excellent.
This was fun! Thanks!
Nice and fun post. Thanks, Chandoo!