Speeding up & Optimizing Excel – Tips for Charting & Formatting [Speedy Spreadsheet Week]

Posted on March 21st, 2012 in Charts and Graphs , Excel Howtos - 12 comments

Speeding up & Optimizing Excel - Tips for Charting & Formatting

Is Excel acting slow & taking ages? As part of our Speedy Spreadsheet Week, today lets talk about optimizing & speeding up Excel by formatting & charting better. Use these tips & ideas to super-charge your sluggish workbook.

No matter how much data you got, how many formulas you wrote, the end users seldom see them on your workbook. They see the finalized dashboard, they play with the model, they look at the report. And if you make poor choices, your end users will thing your workbook is slow.

7 Charting & Formatting Tips to Optimize & Speed up Excel

1. Use picture links / camera snapshots wisely

Picture links (known as camera snapshots in Excel 2003 or earlier) are a blessing in disguise. They can let you create stunning dashboards & reports, but they can also drastically slow-down your workbook. If you add one too many picture links or make they too dynamic, any time you change something on the dashboard, the picture links must be refreshed and that slows Excel down.

Remedy? Simple, use fewer picture links. Limit dynamic changes to minimum. Try using charts instead of picture links and measure the performance. If you have added any animation (thru VBA), get rid off it.

Note: In Excel 2010, the performance of picture links has been improved, but they still slow-down your workbook.

Resources to learn more about dynamic charts & picture links:

2. Do not load too much data in to the charts

Any time you have a chart that depicts more than half-a-dozen series of data, stop and reject the idea. See if you can re-structure the chart so that it shows lesser information or becomes 2 charts. Some ground rules I follow,

  • Never make charts with too many data points.
  • Use form controls or user input to show a sub-set of data instead of everything.
  • Do not customize the charts too much. Instead rely on other techniques like,
    • Using drawing shapes & text-boxes.
    • Using multiple charts
    • Using a mix of charts & cell formatting
  • Group the data and visualize at the group level (works for pivot tables)

Resources to learn about charting better:

3. Stay away from fancy formatting in the charts

Fancy chart formatting options like 3d, shadows, perspective, reflection or gradients are CPU intensive and eye-sore. Even if your chart is rendered in a split second, because of all the additional detail in it, user takes more time to read it and hence perceives your workbook as slow.

Solution? Just use simple formatting. Use these guidelines,

  • Use fewer colors
  • Use fewer fonts (maximum 2 for a chart for best results)
  • Use 2d instead of 3d.
  • Stay away from features like 3d, perspective, shadows, reflections in the chart formatting.
  • If you must use these features, use them on a drawing shape and position it behind the chart.

Resource to learn about chart formatting:

4. Use conditional formatting, in-cell charts instead of charts

With Excel 2007 & 2010, you can create rich conditional formatting that communicates better. So use it instead of charts in some places. Some excellent uses of conditional formatting are,

5. Only format the cells you use

Often we format an entire column or row when we just use a bunch of cells. This used to be fine until Excel 2003 (where the maximum rows are 67k & max columns are 256). With Excel 2007 & 2010, the number of rows & columns in Excel worksheets has gone up significantly. So when you format an entire column you are asking for trouble. Follow below guidelines when formatting your worksheets to improve the performance.

  • Use tables when you are dealing with structured data. This way all the formatting is done automatically and extends only up to the last row / last column.
  • Never format an entire column or row. Just select the cells you use and format them.
  • Use simple formats. This way, even if you have to apply them to additional rows, you can do so faster.
  • Do not apply conditional formatting to very large ranges. This can significantly slowdown your workbook.
  • Hide rows & columns you do not need. This way the temptation to mess with them is gone.
  • Remove worksheets that are not required.
  • Use minimal formatting for non-output worksheets. And hide them if possible.
  • If you want to use very fancy formatting for a cell (multiple colors, multiple fonts etc.) use a text box instead. This way you can format it richer and the workbook remains lighter.

Related: 10 tips to create better & boss-proof Excel workbooks

6. Limit cell styles to a minimum

I have not tested this, but I heard that when you use a lot of cell styles, the workbook becomes slower. So rely on fewer cell styles and use only the built-in styles.

7. Use built-in features instead of 3rd party add-ins

I have nothing against add-ins and I personally use a few to do my work better. But when it comes to charting & formatting, you may want to use whatever is available if speed matters to you most. This is because built-in charts & features tend to be faster & bug-free. Plus they work on all computers.

If you must use 3rd party add-ins, use the ones made by a credible source & thoroughly test them. (Example: Jon’s charting add-ins, add-ins by other MVPs are usually better compared to a random macro code / add-in you found on internet).

More on Excel Optimization & Speeding up:

Read these articles too,

What formatting & charting tips you suggest to speed up Excel?

Most of my work involves producing dashboards & worksheet models – where charts & formatting plays a big role. So I follow pretty much all these tips to make my workbooks responsive.

What about you? What tips you suggest to make Excel faster? How do you format your workbooks & charts so that they look good & act fast? Please share using comments.

12 Responses to “Speeding up & Optimizing Excel – Tips for Charting & Formatting [Speedy Spreadsheet Week]”

  1. Greg says:

    Usually when I dump data into my files to update values, the formatting sometimes go to all rows or columns. So what I typically will do is go to the last row and then the last column and use Ctrl + Shift + end and then delete the cells highlighted. this will remove all unknown formats in the worksheet. Also, after you have done this, you won't see the benefit until you save the document. Sometimes I even have to close and reopen. The direct sign that this has improved is the size of the scroll bar and range.

  2. I have some comments on a couple of the points.

    1. Camera objects

    Tip: I use defined names in conjunction with camera tool objects.
    Each camera object gets a name like so:
    CameraItem01
    Referring to: =IF(PicsOn=1,Sheet1!$C$2:$S$5,"")
    By setting the PicsOn name to 1, the camera objects become "live", by setting the PicsOn name to 0, they become static. That improves performance enormously.

    4: Conditional formatting

    Lots of CF rules can slow down your workbook a lot. And it does not show the calc progress a "normal" recalc does on slow workbooks.

    5. Format whole columns/rows

    as far as I know, there is no problem with formatting entire columns/rows performance-wise, on the contrary, Excel is more efficient when you format an entire column than when you format a couple of 100 rows of a column.

    6. Styles.

    Here I wholeheartedly disagree. I say: Use styles. And use them religously.

    I mean: if you have applied a (custom) style and you need to change a small piece of formatting to make that one cell look right, force yourself to create a new style just for that cell. It forces you to really think about your spreadsheet design and try and streamline it. It also makes it much, much easier to change your sheet's appearance later on. See http://www.jkp-ads.com/articles/styles00.asp

    • Chandoo says:

      Very good insights Jan..

      Camera objects: I often use similar technique to turn off images in my dashboards.

      Formats: Thanks for clearing this. Do you think formatting larger ranges has any impact on macro speeds or it does not matter?

      Styles: Thanks for telling us about this. As I mentioned, I am not sure about the styles, but I am under the impressions that excessive use of styles can bloat the file size.

      • @Chandoo:
        If you stick to formatting entire rows/columns I don't expect macro speed is affected. Better: try it!

        If you use styles properly AND as a replacement of ad-hoc cell formatting, I expect you'll see that the file actually is smaller in size.

        This is because the cells now only have a reference to a single style instead of a reference to a custom cell formatting style.

        Many cell formatting combinations get created if you format your cells in an ad-hoc manner, which was responsible for the dreaded "Too many different cell formats" error in Excel 2003 and older. Excel 2007 and 2010 have a higher limit there, but it does slow down your file with many of them.

        Style bloat in my point of view is what you get by copying and pasting a lot from various other files and thus get Normal 1, Normal 1 1, Normal 1 1 1, ... I have seen workbooks with as many as 6000 styles, all caused by copying and pasting from various differently formatted workbooks.

        Excel 2007 and 2010 have fixed a number of issues regarding copying of styles, but for workbooks with a long editing history, the trouble is already in the workbooks.

  3. PremSivakanthan says:

    Cant emphasise the importance of reducing the amount of formatting in a workbook - this has a suprising impact on workbook size. I've always kept to one font, and no more than three colours - this has worked well for me. Keeping things clean and simple should be the motto when designing any type of report/dashboard that is going to be distributed around the organisation.

    You can also save a few MB's by saving as an xlsb file.

  4. Ron says:

    Has anyone else mentioned that only the first item in the "more ..." section is hyperlinked.

    Prem, have you confirmed by trial that XLSB file size is smaller than same XLSX file? Sorry, I just tried it with a small, simple XLSM file. I was surprised to see you are correct. File went from 40kb to 37kb. I thought that the compression of the new file would make the new file smaller.

    • Hui... says:

      @Ron
      All Excel files have a minimum overhead that they have to include which is around 8KB, just to store a simple number or letter.
      So with a small file of 40KB you will not see a huge improvement in file size
      With files greater than 10MB you will see large improvements in size.
      The compression gained also depends on what the contents of the file include. That is straight numbers, text and formulas can be greatly compressed whereas files that contain a lot of objects especially pictures gain very little from using *.xlsb files.

    • Chandoo says:

      @Ron.. the other articles are yet to be published. All the links will be updated by Tuesday (27th March).

  5. Mil says:

    Hi,

    I have a need for x,y scatter chart to have arround 30 data series.
    like this:
    http://i65.tinypic.com/jra8lc.jpg
    Also I have multiple of such charts in one excel file.

    Is there any way to make excel faster, because it is irritatingly slow?
    (though my PC config. is quite on the level)

    Thanks in advance!!!

    • Hui... says:

      @Mil
      30 series won't be the issue
      It is the number of points in the series
      Also remove all fancy modifications, like shadows, fancy fills etc

      I'd suggest asking the question in the Chandoo.org Forums http://forum.chandoo.org/
      Attach a sample file with an example of what you are after

      • Mil says:

        @Hui

        I've already removed all fancy mod. The problem is there are also a lot of data points in one series.
        Thanks for the advice!

        • Hui... says:

          @Mil

          Do you really need every data point ?

          Where is the chart being presented Screen or Report

          On a screen you are unlikely to use more than 800 pixels for the chart area
          So using any more than about 250 points is not adding values

          On an A4 chart in landscape lets say the chart area is 6" long and at 300dpi that is 2000 pixels
          Once again using more than 800-1000 points will not add any value

          I have seen charts with 30,000+ points and when this is explained and a work around shown people appreciate the speed up

          For a work around try setting up an area where you select say every x'th point using an Offset or Index Function
          Then plot that data

          I'd suggest asking the question in the Chandoo.org Forums http://forum.chandoo.org/
          Attach a sample file with an example of what you are after

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