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.
28 Responses to “2010 Calendar – Excel Template [Downloads]”
[...] Download and print the calendars today. You can add notes to individual dates or complete … [...] Uni Ego / Free 2010 Calendar – Download and Print Year 2010 Calendar today [...]
Any chance on a 2016 calendar?
Afternoon,
I have one similar calander that I added conditional formatting to so that I could highlight any planned factory holidays. I think i "borrowed" the formula from another calander so I won't post it here.
I also added week numbers to it using the formula =WEEKNUM(MAX(C6:I6)) Where C6:I6 is the range of dates in that give week. It works fine on most of the months but return strange values on other months (Week 6 in October?) I can't see any logic behind why it does this.
Any suggestions for an alternative formula to give the week numbers?
Regards,
William
Hi Chandoo,
I've added a new feature on your spreadsheet.
This control can be useful for all the sheets where you need to check dates.
Cheers
http://cid-69a78592a23a8438.skydrive.live.com/self.aspx/.Public/2010-calendar%5E_Miguel.xls
Hi Chandoo,
Nice calendar.
Till now whichever calendar I saw in Excel, it contained only the outline sheet.
Good to see monthly views and the mini view too.
Liked the mini view much. 🙂
-Nimesh
@William: This weeknum may be because the input dates to max are not properly formatting as excel dates.
Good tip on the conditional formatting and holidays btw...
@Migueal: Now that is super awesome. This is the reason why I love to blog. Readers will always one up me with such cool alternatives. Thank you for sharing this with us.
@Nimesh: You are welcome 🙂
is it possible to get the Notes section on the outline page to display the notes added to the month page for a specific date?
So if you add thing for January 2nd, and then select January 2nd those notes appear on the outline page
@Shish... You can do that using some formula magic. I would not recommend pushing excel to that as outlook / google calendar / icalc etc. do exactly that much more elegantly.
[...] Perpetual Excel Calendar – Free Downloadable Template [...]
Happy christmas to all of you!
This is really awesome. The nicest calender I've seen for Excel. I also like Miguels version of the sheet.
Just one "feature" is missing to me. As I live in Germany - where weeks start on Monday - I'd like to change this. Could someone please give me a hint how to do this?
Thanks in advance
Jörg
Hi Chandoo, I’ve added some new features on your spreadsheet with your permission.
Check it here:
http://cid-6b219f16da7128e3.skydrive.live.com/self.aspx/.Public/Calendar%5E_Pedro.xlsm
Miguel, this calendar is translated to Spanish language.
Jörg, this new approach allows us to start weeks on Monday.
Also it's possible to start weeks on Sunday if you enable Excel macros and push the arrows.
Best Regards,
Pedro.
@Pedro.. superb stuff.. thanks for sharing the file with all of us.
Hi Chandoo, for dates before March 1, 1900 our calendars are wrong.
In Microsoft Excel, DATE, EOMONTH, WEEKDAY functions return an incorrect result between Monday, January 1, 1900 and Wednesday, February 28, 1900.
See this page: http://support.microsoft.com/kb/214326/en-us/
Microsoft Excel incorrectly assumes that the year 1900 is a leap year in all Excel versions.
That's the reason why our calendar versions only work from March, 1, 1900 until December, 31, 9999.
Your comments are welcome.
Pedro.
@Pedro.. Thanks for pointing that out. wow... This reminds me of the Joel Spolsky's first BillG review - http://www.joelonsoftware.com/items/2006/06/16.html (read it, I am sure you would love it.) when Bill out of blue asks about date time implementations for VBA (which Joel is the program manager for...)
Thanks for sharing the URL too... Here is a specially made, chocolate sprinkled, extra fluffy donut for you 🙂
Hi Chandoo, thanks a lot for the donut but I prefer it without chocolate!
Always it's good to know a little history of Excel.
The Joel Spolsky’s last BillG Excel review was about the "Hall of Tortured Souls"
(See this Excel 95 Easter Egg here: http://www.eeggs.com/items/719.html)
Do not miss the humor!
@Chandoo.. I just return with a new calendar version.
http://cid-6b219f16da7128e3.skydrive.live.com/self.aspx/.Public/calendar-pedrowave.xltx
It helped me to practice conditional formatting, formulas to show check boxes, data validation drop down list, find out Thanksgiving Day's date for any year, how to find dates of public holidays using Excel, all reading your wonderful posts!
Perpetual Calendar Spanish version starting weeks on Monday:
http://cid-6b219f16da7128e3.skydrive.live.com/self.aspx/.Public/calendario-pedrowave.xltx
Main characteristics:
- Not macros.
- Select a year from 1900 to 9999 with a dropdown listbox.
- All date fields with the real date format.
- Easy language change of day of the week and month names because are also dates.
- Hide Saturdays and/or Sundays.
- Week starting on Sunday or Monday.
- Week and month numbers.
- Hyperlink between sheets.
- Consistent colors to Holidays, Diary and Events dates.
- Easy change of Holidays by country.
- Include 80 World Days and you can add more.
- A diary with my birthday and 50 more programable appointments.
- Check box to hide individual dates or all.
- Holidays, diary and events text are showed on each month's sheet.
- Ranges defined with Name Manager variables.
I'll appreciate if you make me some suggestions to improve this calendar.
Pedro.
Please, I need help!
I like all calendar from Pedro, thank you for them. Let me show my problem:
I have 2 excel cells (for example AE12 and AE13) which mean the starting and the ending date of my duty. I need a macro to insert sheets with label YEAR. MONTH (for example 2010. August or similar) with the proper datas between the two dates. Is it possible?
Thank you for reading me and sorry about my terribel english! 🙂
Hello Pedro,
Thanks so much for the modified calendar template. I love the extra functionality you added. Is there any way you could upload an unlocked version? I wanted to change some of the comments and data validation so I could use it for one of my applications.
As for feedback on potential improvements, with all the additions you made the file runs pretty slow. I'm sure this has to do with all the interconnectivity between the various tabs, but if there is a way to use less memory via more efficient formulas or something else I think this would make it easier to use. I have a brand new computer and with it running alone the response was pretty slow. One of the changes I'm making is changing the order of the months to match my company's fiscal year, so maybe something to automate a change like that could be useful.
Cheers,
Peter
Peter, my calendars are unlocked but you need Excel 2007 and 2010 versions to open them.
Now I return with a new Programmable Task Calendar:
http://cid-6b219f16da7128e3.office.live.com/view.aspx/.Public/Calendario%20de%20Tareas.xlsx
Wath an introductory video here:
http://pedrowave.blogspot.com/2010/10/programmable-task-calendar.html
This new calendar allows to select the start month to match the school and fiscal year.
This is great stuff Chandoo and company
Wanted to know if someone had built something similar
I need to store one Excel Sheet on this calendar that has all the holidays
US Holidays appear in RED
UK Holidays appear in Blue
Meetings appear in Green
Submissions appear in Orange
Is there a way I can store the list in a separate worksheet and all the calendars get updated with this?
Thanks
[...] Calendars: Year 2010 Excel Calendar | Year 2009 Excel [...]
please tell me "how to convert Rs.10000/- in to words through excel formula
[...] is all! http://chandoo.org/wp/2009/12/11/2010-calendar-excel-template-downloads/ See more Templates at http://www.vertex42.com/ Share this:Like this:LikeBe the first to like this [...]
Greetings,
Thanks for this wonderful excel vacation tracker. I notice that the tracker only has three months November, December and January 2015, however, I would like to add the other ten months for 2014. Can you please instruct me on how I can add the other months?
Thanking you in advance.
Hi Chandoo,
Calendar: can this be printed as single sheet 8.5x11 inch per month
kanu
@Kanu
Yes,
You can resize it to fit
WOW! I just searching some of like this, that help me.
Thank you for sharing.