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.
30 Responses to “Rescue oddly shaped data – Battle between Formulas, VBA and Power Query”
Nice use of Power Query! Power Query is simply awesome! But somehow a lot of people are punishing themselves by not using it (not learning it).
An imperfect 4th approach for consideration... no codes at all...
Select myrange.
Go to Special --> Blank
Delete Cell --> Shift cell left
90% done... now we just need to move the data of 2nd column to the bottom of 1st column
Of course... Power Query is the best.
Cheers,
There is another way but it involves multiple steps:
Copy the values in column E, move the cursor to F5, Paste Special with Skip Blanks, OK
Copy the values in column D, move the cursor to F8, Paste Special with Skip Blanks, OK
And so on.
This works perfectly, albeit a little clumsily apart from the values in B17 and C16, which can be moved with simple copy and paste
Power Query Forever! I do not know how I survived for so long without knowing and using this tool, I can not recommend it to my colleagues, but by the way they prefer to suffer to learn.
My congratulations here from Brazil.
I rolled my eyes when I saw that data
Using decimal places is a nice trick to order data, thanks for that
And tweaking the first formula a bit, you can use OFFSET instead of INDIRECT
=OFFSET($A$1, MIN(IF(myrange, ROW(myrange)), ROWS(A$1:A1))-1, RIGHT(TEXT(MIN(IF(myrange, ROW(myrange) + COLUMN(myrange)*0.00001), ROWS(A$1:A1)), ".00000"), 5)-1)
Tried the above formula with the downloaded oddly shaped data file and I could not get it to work. I get #value without ctrl+shift+enter, and #ref with ctrl+shift+enter.
Sorry, it was SMALL, not MIN.
Add with CTRL+SHIFT+ENTER.
Thank you for your formula. Like the indirect formula I tested this one in older versions of EXCEL and it worked without ALTERATION in EXCEL 95. Very impressive.
Too complicated
Use =Sum to summarize all the sells to the left and Bobs Your Uncle
@Bertie... I am afraid that won't work when you have more than one value in a row.
I tested this formula in versions of Excel all the way back to Excel 95
=IF(ISERROR(INDIRECT("R"&SUBSTITUTE(TEXT(SMALL(IF(MyRange"",ROW(MyRange)+COLUMN(MyRange)*0.00001),ROWS(A$1:A9)),"00000.00000"),".","C"),FALSE)),"",(INDIRECT("R"&SUBSTITUTE(TEXT(SMALL(IF(MyRange"",ROW(MyRange)+COLUMN(MyRange)*0.00001),ROWS(A$1:A9)),"00000.00000"),".","C"),FALSE)))
So there are multiple ways of cleaning up messy data by formulas.
Wow.. Excel 95. Who knew people still use that. But as you have shown, Excel has all these beautiful and powerful functions for 23 years. It has data sciency stuff before DS was even a thing.
I had a problem with pasting the formula in the original post.
Formula should be: =IF(ISERROR(INDIRECT("R"&SUBSTITUTE(TEXT(SMALL(IF(myrange"",ROW(myrange)+COLUMN(myrange)*0.00001),ROWS(A$1:A1)),"00000.00000"),".","C"),FALSE)),"",(INDIRECT("R"&SUBSTITUTE(TEXT(SMALL(IF(myrange"",ROW(myrange)+COLUMN(myrange)*0.00001),ROWS(A$1:A1)),"00000.00000"),".","C"),FALSE)))
EXCEL even in a 16 bit version, is a very robust and capable program.
I don't like the VBA code. If you have a blank row in MyRange, the last entry in the range is doubled up in the paste.here range.
Not really. The macro is writing one cell at a time from paste.here. You have to clean the range before, which I was too lazy to write. But a line like Range(range("paste.here"), range("paste.here").end(xldown)).clearcontents should do the trick.
Adding Range(range("paste.here"), range("paste.here").end(xldown)).clearcontents fixed the problem.
for step split column by delimiter i am not getting option of split into rows or columns. Can you help me in this
Thanks Chandoo for promoting Power Query.
To simplify further, you can "Unpivot Columns" instead of right click on the newly created column and split it by comma in to rows in step 3 of Power Query.
i used
=LOOKUP(10000,B5:F5)
and got the answers. I just plagiarized this formula somewhere and use it, maybe you can explain why it works.
Regards
@Johan... I am not sure if the formula works correctly. When I tested it with the sample data in this post, it showed #N/As in two cells. Essentially, it will only give first value in each row. So if a row has multiple values, then subsequent values are missed. LOOKUP() function goes thru a list and finds the first value that is less than or equal to the input - in this case 10000 in B5:F5.
I have the need to convert pdf's to excel on occasion and they often come out a mess like this. I have used:
Cell G2 =COUNT(myrange)
Cell G3 =IFERROR(IF(G2-1<1,"",G2-1),"") copied down to G100
Cell H2 =IFERROR(LARGE(myrange,G2),"") copied down to H100
Waouw...
=IFERROR(INDIRECT("R" & SUBSTITUTE(TEXT(SMALL(IF(myrange "", ROW(myrange) + COLUMN(myrange)*0.00001),
ROWS(A$1:A1)), "00000.00000"), ".", "C"), FALSE), "")
but CTRL Shift Enter with {} before and after 🙂 😀
Here's a way with pivot table
https://www.bookkempt.com/2018/02/aligning-non-contiguous-data.html
This is brilliant. Bookmarked 🙂
Another possibility.
This assumes that you have a row index 'k' to use in the SMALL function and a column index 'h' to identify the columns of 'myRange'.
If you define 'coord' to refer to
=k+h/10 [assuming h<10]
then it will be possible to recover values later based upon location within 'myRange'. The formula 'nb' that identifies non-blanks by coordinates is given by
= SMALL( IF(myRange"", coord), k )
Finally, to unpick the pieces
= INDEX( myRange, INT(nb), 10*MOD(nb, 1) )
Whilst I am here and making trouble the PQ solution is also a tad over-complicated. All that is needed is to unpivot the entire table and remove the Attribute column.
The advanced editor would show
let
Source = Excel.CurrentWorkbook(){[Name="myRange"]}[Content],
#"Unpivoted Columns" = Table.UnpivotOtherColumns(Source, {}, "Attribute", "Value"),
#"Removed Columns" = Table.RemoveColumns(#"Unpivoted Columns",{"Attribute"})
in
#"Removed Columns"
1.fill the blank cells with 0
2.the requested column value=sum of those mess number column
but this can be used in only one column has value
Chandoo
And if we use the formula SEARCH (100000000, B5: F5)
JC
Another approach with Power Query, it will still work if the number of columns changed:
let
Source = Excel.CurrentWorkbook(){[Name="myrange"]}[Content],
#"Added Custom" = Table.AddColumn(Source, "List", each Record.ToList(_)),
#"Removed Other Columns" = Table.SelectColumns(#"Added Custom",{"List"}),
#"Expanded LIst" = Table.ExpandListColumn(#"Removed Other Columns", "List"),
#"Filtered Rows" = Table.SelectRows(#"Expanded LIst", each ([List] null))
in
#"Filtered Rows"
Cool idea to use Record.ToList as added column. Thanks for sharing this.
Nowadays, you can just use TOCOL on Excel 2024, MS 365, and Web Excel. It has a parameter to ignore blanks/errors/both.