The reason why you got this error is because an Excel file can only have approximately 4,000 different combinations of cell formats.  At first this might seem like a lot, but think about all the unique formatting characteristics that can be applied to a cell.

• Fonts: including the font, font size, bold, italic, underline, strikethrough, superscript, subscript, color, etc.
• Borders: including which side of the cell has a border (top, left, right, or bottom), border color, border thickness (or weight), etc.
• Fills: including fill color, and patterns.
• Number formatting: such as General, Number, Currency, Accounting, Date, Time, Percentage, Fraction, Scientific, Text, Special, or Custom.  Not to mention the number of decimal places shown.
• Alignment: Top, bottom, left, right, centered, centered across selection, indented, orientation degrees, wrapped text, shrink to fit, merged cells, text direction, etc.

Any unique combination of the above cell formats counts towards the 4,000 limit, however if several cells share exactly the same formatting, it only counts as one.

For example, assuming that all other formats are the same, a 3×3 cell “boxed” with a border going around it would have nine different cell formats, considering that no cell in the group would share the same side border formatting (see below).

 To fix this, simplify the formats of the cells in your file, by using some of the suggestions below:

• Use only one or two standard fonts.  For example, if you want your headings to be bold, and the data to be in a regular style, do so consistently.
• Use consistent borders in your worksheets.  Maybe just box in headings and your data points to make it easier for your files users to read.
• Clear out unnecessary fill colors and patterns.
• Make sure your numbers are consistently presented (i.e. percentages are shown as such with the same number of decimal points, dollars are shown in the currency, or accounting format, etc.).

Also, consider clearing the formats of blank cells.  To do this, click Edit | Go To | Special | Blanks.  This will highlight all cells that do not contain data.  Next, click Edit | Clear | Formats (or All).  This will clear all the blank cells of any formatting that have been applied to them.  Be careful however, as this could have unintended consequences if you’ve filled the cells in a row or column to act as a “border” between sections in your worksheet, or if you’ve used the Center Across Selection formatting.

After done simplifying your cell formats across your entire file, save, close, and then re-open before adding any new cell formats.

The question I want to solve is: if I sell all the shares that have produced a gain, how many of the shares should I sell at a loss in order to offset the gains, and the resulting taxes?

To do this, I set up my spreadsheet like the one below:

Note: these are not the actual amounts I used in my own personal situation.  They are only provided for illustration purposes.

Download the example file here.

In cell G8 (labeled “Total Losses” in cell F8), I have the following formula: =(G10*C3)-(G10*E3), which I want to equal the total gains amount, of $1,936.10.  Right now it is showing a zero value because I haven’t determined how many shares need to be sold at a loss to equal the gains.

To do this, select cell G8, then click Tools | Goal Seek.  In the box that pops up, enter the following:

• Set cell: Keep as G8.  If it isn’t G8, enter G8 here.
• To value: Enter 1,936.10, as this is the value we wish to set the losses to.
• By changing cell: Enter cell G9, as you want to determine how many shares need to be sold in order to break even.
• Click OK

The result will tell you that you should sell 43.54 shares in order to break even.

For more information on Excel’s Goal Seek feature, take a look at the post Goal Seek to Solve a Problem.

First, some background on what it does.  Goal Seek is essentially the answer to every middle school aged kid’s math test word problem.  It is best used when you know the answer to the problem you’re trying to solve, but don’t know all the inputs.

For example, a simple word problem might be “You have 432 sheets of paper to give out to a class of 36 students.  How many sheets of paper does each student get.”  Well you know that 36 multiplied by something will give you 432, but you don’t know what that number is.  You could divide 432 by 36 to get the answer, but let’s assume that isn’t possible right now.  With Goal Seek, you need several things:

• An answer expressed as a formula, in this case 432 is equal to 36 times something.  Don’t worry, the result of the formula doesn’t have to equal 432 yet.  That’s the magic of Goal Seek.
• You need one part of the equation, in this case 36.

To start, type the following into your spreadsheet in the cells indicated.

Next, open Goal Seek (Tools | Goal Seek, or Data tab on the Excel 2007 ribbon | What If Analysis | Goal Seek).

You are now going to be asked for three things. 

1. Set Cell: this is the reference to the cell that contains your formula, in which you want Excel to produce your answer of 432.  In our example it should be A3.  Note: the Set Cell MUST contain a formula or function.
2. To Value: this is the value you want in your Set Cell (A3).  The value here should be 432.
3. By Changing Cell: Since we know that the formula in cell A3 is correct, and the value of 36 in cell A1 is correct, we want Excel to produce the answer of 432 by changing cell A2.  Type A2 in this box.  Note: the Changing Cell MUST contain a value.
4. Click OK.

After clicking OK, Excel will attempt to find a solution to the equation.  Once it does, it will enter the missing number in cell A2 and your formula should now equal 432.

Obviously this is a basic example, and doesn’t use Goal Seek’s capabilities to their fullest extent.  Let’s take another example that looks at a company’s sales by product to get their desired level of revenue.

XYZ Company makes four different products, Product A, Product B, Product C, and Product D.  The company can produce 1,000, 750, 500, and 100 of each product respectively.  The products also sell for $15, $20, $35, and $50 respectively.  Their maximum revenue for products produced that month, therefore is as follows:

Now say the company feels that their underdog, Product D, could be producing much more.  They also want their revenues to be 60,000.  How many more of Product D will they need to produce?

To figure this out, run Goal Seek just like before, except this time, the “Set Cell” is cell D6, “To Value” is 60,000, and the “By Changing Cell” is cell B5.  After clicking OK, you’ll notice that Excel has changed the value in cell B5 to 250, indicating that you will need to increase production of Product D to 250 units from 100 in order to have revenues of $60,000, assuming everything else remains the same.

For example, when balancing a checkbook, you could write out your bank balance and manually add or subtract the deposits and checks that haven’t cleared the bank yet.  Or, you could type your bank balance into Excel, type the list of checks and deposits and have Excel do the math for you.

You could also add a list of numbers together in one cell the opposite way from how you would calculate them on a calculator.  If you have the following list of numbers: 8, 17, 49, 32, 19, you would add them on a calculator by typing 8+17+49+32+19= to produce 125.  In Excel, the equals sign is on the opposite side of the equation.  You simply type =8+17+49+32+19 hit Enter and the cell will display the result, 125.

You can do this with all the familiar operators found on a calculator (add, subtract, multiply, and divide), as follows.

So, while Excel is more than just a calculator, it can still perform various functions like a calculator.

In addition to the new programs, Microsoft is also introducing Office Web Applications, which compliments Word, Excel, PowerPoint, and OneNote to allow you to access your files from anywhere with an internet connection.  It also allows you to share documents with others and even gives you the ability to work simultaneously on the same document.  Further adding to their product offerings is Office Mobile, which allows you to view Word, Excel, and PowerPoint files on a mobile version of the software.  Email will also be easier to manage with Outlook Mobile.

OK, so enough with the Office features, what’s new in Excel 2010?

Spreadsheets can now be run in your web browser, and be published to the web via the desktop version.  The browser version does not have as many features as the desktop version, however it is an improvement over Google Spreadsheets.  Additionally, a new analytic feature is called Sparklines, which produce a visual trend of a data set over time similar to a chart, except the Sparkline is contained within a single cell.  For example, if you’re tracking monthly sales of a product, you can set a Sparkline that will show the peaks and valleys that the data produces.

One thing users of Excel 2007 (and other Office 2007 programs) who are just getting used to the new Ribbon will not have to worry about is learning another new user interface.  The ribbon should remain essentially the same as in the 2007 version, except for a few new features.

This post will get updated as I discover new features, so please bookmark it and check back often.

Excel helps the user by inserting labels in key points to help the user identify what they are looking at.  If you have a dynamic set of data (that is, it can change and represent different different sets of data) that feeds a chart, you might not want to use Excel’s default data labels.  Luckily Excel will allow you to link certain labels to a cell in your file, which will update the label’s value each time the cell value changes.

To do this, simply click on the label so that there is a box surrounding it.  Then click in the formula bar and type “=A1″ (assuming you wish to link the label to cell A1).  Hit Enter and you’re all set!

Linking the chart’s labels is useful when, for example, you have some monthly sales information set up so that when you type “Monthly” in cell A1, it displays the data by month, and when you type “Quarterly” in cell A1 it displays it by quarter.  Essentially its the same data, just aggregated a little differently. 

Having a chart that is as dynamic as the data would be nice so that you don’t have to keep changing the chart title from “Monthly Sales Data” to “Quarterly Sales Data”, or the X-Axis label from “Monthly” to “Quarterly”, and back again each time you change the views.

To illustrate how to create a UDF, we’ll create a function that calculates fuel consumption in miles per gallon.

• First, open a new Excel workbook.
• Open VBA (Alt+F11)
• Right click the workbook’s name (i.e. VBAProject (Book1))and select Insert | Module

In order to calculate your vehicle’s fuel consumption in miles per gallon, you’ll need to know a couple things:

• How many miles driven (ending miles less beginning miles)
• Number of gallons used 
• Miles per Gallon = (Ending Miles – Beginning Miles) / Gallons Used

Now, from the new module you opened in VBA, begin typing your function as follows.


Function MPG(BeginningMiles As Integer, EndingMiles As Integer, Gallons As Single)
     MPG = (EndingMiles - BeginningMiles) / Gallons
End Function

After entering the UDF in your module, return back to the Excel workbook and test it out. 

Take a look at the example below to see how this function works the same way any built in function would work.

You can create your own functions to do just about any calculation you can think of, as well as manipulating text.

 These functions can be saved in the workbook you’re working in, or can be saved as an add-in if you wish to use it in more than one workbook.

To save the workbook as an add-in, simply click File | Save As enter a name for the file, then change the file type to Microsoft Excel Add-In (*.xla).  In Excel 2007, you can then import the add-in by clicking Excel Options after clicking the Office Button, then clicking Add-Ins.  Towards the bottom of the screen, select Manage: Excel Add-Ins and click Go.  In earlier versions of Excel, click Tools | Add-Ins.  On the next screen, click Browse and find the location of your Add-In.  Make sure it is checked in the list, and hit OK.  You should now be able to access your Add-In in any file you’re using.

You can use Data Validation to ensure that no duplicate values can be entered into your list. If a user accidentally enters a duplicate, an error message will pop-up telling them that they have entered an invalid value.

To do this, follow the steps below.

• Select the column where you want your list of unique values to appear (for illustration purposes we’ll assume it is column A).
• Click Data | Validation.
• On the Data Validation window’s Settings tab, select Allow: Custom.
• In the Formula box, type the following formula: =MATCH(A1,$A:$A,0)=ROW(A1) (if you’re using this in a different column than column A, change the “A1″ and “$A”‘s in the formula to whichever column you’re using)
• Click OK.

Now begin to type your list of unique values. If you should happen to accidentally enter one twice, you’ll see the following error message pop-up:

You can click “Retry” to re-enter a value in the same cell, or “Cancel” to delete the duplicate value.

**UPDATE**

To have a “one click” availability to this tip, use the following macro code.  Again, like the formula above, change the “A1″ and “$A”‘s to whichever column you’re using.

Sub Duplicate_Validation()
'
'MACROS BY EXCELZOOM.COM
With Selection.Validation
.Delete
.Add Type:=xlValidateCustom, AlertStyle:=xlValidAlertStop, Operator:= _
xlBetween, Formula1:="=MATCH(A1,$A:$A,0)=ROW(A1)"
.IgnoreBlank = True
.InCellDropdown = True
.InputTitle = ""
.ErrorTitle = ""
.InputMessage = ""
.ErrorMessage = ""
.ShowInput = True
.ShowError = True
End With
End Sub


The example in the previous tip emphasized the importance of having consistent information when summarizing information in a PivotTable. Another use is to store lists of information, which could be anything, but in this example, I’m going to use website addresses.

Say you do a lot of research on several different topics, and summarize the results in a different spreadsheet for each topic. You could store all the bookmarks in your web browser, and chances are you already do. The problem with this is that if you’re only using a handful of bookmarks for one topic out of the many you have saved, you could end up searching through a lot of bookmarks to find the sites you need.

If you instead take the time up front to compile a list of sites you use frequently for a particular topic, you can use data validation to display them in one cell on your spreadsheet with another “clickable” cell to open the site in your web browser.

To do this, follow the steps below.

• Select the cell where you want your list of websites to appear (for illustration purposes I’ll assume your list will appear in cell A1).
• Click Data | Validation.
• On the Data Validation window’s Settings tab, select Allow: List, and make sure the In-cell dropdown box is checked.
• In the Source box, refer to the range of cells in the same worksheet that contains your website list, or refer to a named range elsewhere in your workbook.
• Click OK.

When you select cell A1, you should now see the list of websites when you click the arrow to the right of the cell. Now select cell B1. This is where we are going to put some text that becomes “clickable”, sort of like a link on a website.

In cell B1, type =HYPERLINK(A1,”GO”). Now whenever you change the website in cell A1, using the drop down list, you can click the words “GO” in cell B1 go to that site. It’s like having your own bookmark system in Excel!

If you want to display this information in a cell in your file, enter the following formula in the cell where you want the name to appear:
=MID(CELL(“filename”,A1),FIND(“]”,CELL(“filename”,A1))+1,256)

Anytime you change your sheet’s name, the formula will automatically update, so you never have to edit the name in the worksheet as well.

If you only need the information on a printout and don’t want it displayed in a cell, you can edit the sheet’s header/footer. Click View | Header and Footer | then Custom Header or Custom Footer, depending on where you want the name to appear. Determine where you want the name to appear (Left, Center, or Right) and click the worksheet button (third from the right) that looks like a worksheet with three tabs below it.