Tips to Handle Slow Excel Spreadsheets

Suffering from Slow Excel Spreadsheets? Try these 10 tips to SPEED-UP your Excel

If there is one thing that unites us all, it has to be the frustration to keep up with a slow excel spreadsheets.

While the impact on the performance may be negligible when there is less data, it becomes more profound as you add more and more data/calculations to the workbook.

9 out of 10 times, an Excel user would complain about the slow Excel spreadsheets. And there is hardly anything you can do about it.

Well, that’s NOT completely true.

The way Excel has been made, it does get slow with large data sets. However, there are many speed-up tricks you can use to improve the performance of a slow Excel spreadsheet.

10 Tips to Handle Slow Excel Spreadsheets

Here are 10 tips to give your slow Excel spreadsheet a little speed boost, and save you some time and frustration (click to jump to that specific section).

1. Avoid Volatile Functions (you must).
2. Use Helper Columns.
3. Avoid Array Formulas (if you can).
4. Use Conditional Formatting with Caution.
5. Use Excel Tables and Named Ranges.
6. Convert Unused Formulas to Values.
7. Keep All Referenced Data in One Sheet.
8. Avoid Using Entire Row/Column in References.
9. Use Manual Calculation Mode.
10. Use Faster Formula Techniques.

1. Avoid Volatile Formulas

Volatile formulas are called so because of a reason. Functions such as NOW, TODAY, INDIRECT, RAND, OFFSET etc. recalculate every time there is a change in the workbook.

For example, if you use NOW function in a cell, every time there is a change in the worksheet, the formula would be recalculated and the cell value would update.

This takes additional processing speed and you end up with a slow excel workbook.

As a rule of thumb, avoid volatile formulas. And if you can’t, try and minimize its use.

2. Use Helper Columns

Helper columns are one of the most under-rated design constructs in Excel. I have seen many people shy away from creating helper columns.

DON’T DO That.

The biggest benefit of using ‘Helper Columns’ is that it may help you avoid array formulas.

Now don’t get me wrong. I am not against array formulas. Rather I believe these could be awesome in some situations. But it when you try to do it all with one long formula, it does impact the performance of your Excel workbook. A couple of array formulas here and there shouldn’t hurt, but in case you need to use it in many places, consider using helper columns.

Here are some Examples where helper columns are used:

• Automatically Sort Data in Alphabetical Order using Formula.
• Dynamic Excel Filter – Extract Data as you Type.
• Creating Multiple Drop-down Lists in Excel without Repetition.

3. Avoid Array Formulas

Array formulas have its own merits – but speed is not one of those.

As explained above, array formulas can take up a lot of data (cell references), analyze it, and give you the result. But doing that takes time.

If there is a way to avoid array formulas (such as using helper column), always take that road.

4. Use Conditional Formatting with Caution

I absolutely love conditional formatting. It makes bland data look so beautiful. Instead of doing the comparison yourself, now you can simply look at a cell’s color or icon and you’d know how it compares with others.

But.. here is the problem.

Not many Excel users know that Excel Conditional Formatting is volatile. While you may not notice the difference with small data sets, it can result in a slow excel spreadsheet if applied on large data sets, or applied multiple times.

Word of advice – Use it Cautiously.

5. Use Excel Tables and Named Ranges

Excel Table and Named Ranges are two amazing features that hold your data and makes referencing super easy. It may take a while to get used to it, but when you start using it, life becomes easy and fast.

In creating data-driven dashboards, it is almost always a good idea to convert your data into an Excel Table.

It also has an added advantage of making your formulas more comprehensible.

For example, what’s easier to understand?

=Sales Price-Cost Price OR =SUM(A1:A10)-SUM(G1:G10)

6. Convert Unused Formulas to Static Values

This is a no-brainer. When you don’t need it, don’t keep it.

Lots of formulas would result in a slow Excel workbook. And if you have formulas that are not even being used – you know who to blame. As a rule of thumb, if you don’t need formulas, it’s better to convert them into a static value (by pasting as values).

Read More: How to quickly convert formulas to values.

7. Keep All Referenced Data in One Sheet

This may not always be possible, but if you can do this, I guarantee your Excel sheet would become faster.

The logic is simple – formulas in your worksheet don’t have to go far to get the data when it is right next to it in the same sheet.

8. Avoid Using the Entire Row/Column as Reference (A:A)

The only reason I have this one on the list is that I see a lot of people using the entire row/column reference in formulas. This is a bad practice and should be avoided.

While you may think that the row/column only has a few cells with data, Excel doesn’t think that way. When you reference an entire row/column, Excel acts it as a good servant and check it anyways. That takes more time for calculations.

9. Use Manual Calculation Mode

I am just repeating what million people have already said in various forums and blogs. Using Manual calculation gives you the flexibility to tell excel when to calculate, rather than Excel taking its own decisions. This is not something that speeds up your Excel workbook, but if you have a slow Excel spreadsheet, it definitely saves time by not making Excel recalculate again and again.

• To switch to manual mode, go to Formula Tab –> Calculation Options –> Manual (press F9 key to recalculate)

10. Use Faster Formulas Techniques

Excel gives you a lot of formulas and formula-combos to do the same thing. It is best to identify and use the fastest ones.

Here are a couple of examples:

• Use IFERROR instead of IF and ISERROR combo (unless you are using Excel 2003 or earlier, which does not have IFERROR).
• Use MAX(A1,0) instead do IF(A1>0,A1,0) – This is a cool tip that I learned from Mr. Excel aka Bill Jelen. His research shows that MAX option is 40% faster than IF option (and I am ready to take this stat on his face value).
• Use the INDEX/MATCH combo, instead of VLOOKUP – This may raise a lot of eyebrows, but the truth is, there is no way VLOOKUP can be faster if you have 100’s of columns of data. The world is moving towards INDEX/MATCH, and you should make the shift too.
  [If you are still confused about what to use, here is a head-on-head comparison of VLOOKUP Vs. INDEX/MATCH].
• Use — (double negatives) to convert TRUE’s and FALSE’s to 1’s and 0’s (instead of multiplying it by 1 or adding 0 to it). The speed improvement is noticeable in large data sets.

Is this an exhaustive list? Absolutely NOT. These are some good ones that I think are worth sharing as a starting point. If you are looking to master Excel-Speed-Up techniques, there is some good work done by a lot of Excel experts.

Here are some sources you may find useful:

• 75 Speed-up tips by Chandoo (smartly done by crowdsourcing).
• Decision Models Website.
• Mr. Excel Message Board (explore this and you would find tons of tips).

I am sure you also have many tips that can help tackle slow excel spreadsheets. Do share it with us here in the comment section.

I also have one request. The pain of working with a slow excel spreadsheet is something many of us experience on a daily basis. If you find these techniques useful. share it with others. Ease their pain, and earn some goodness