Finding the number of non-blank columns in an Excel sheet using VBA

How do I find the number of used columns in an Excel sheet using VBA?

Dim lastRow As Long
lastRow = Sheet1.Range("A" & Rows.Count).End(xlUp).Row
MsgBox lastRow

Using the above VBA I'm able to find the number of rows. But how do I find the number of columns in my given excel file?

Your example code gets the row number of the last non-blank cell in the current column, and can be rewritten as follows:

Dim lastRow As Long
lastRow = Sheet1.Cells(Rows.Count, 1).End(xlUp).Row
MsgBox lastRow

It is then easy to see that the equivalent code to get the column number of the last non-blank cell in the current row is:

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox lastColumn

This may also be of use to you:

With Sheet1.UsedRange
    MsgBox .Rows.Count & " rows and " & .Columns.Count & " columns"
End With

but be aware that if column A and/or row 1 are blank, then this will not yield the same result as the other examples above. For more, read up on the UsedRange property.

Jean-François Corbett's answer is perfect. To be exhaustive I would just like to add that with some restrictons you could also use UsedRange.Columns.Count or UsedRange.Rows.Count.
The problem is that UsedRange is not always updated when deleting rows/columns (at least until you reopen the workbook).

It's possible you forgot a sheet1 each time somewhere before the columns.count, or it will count the activesheet columns and not the sheet1's.

Also, shouldn't it be xltoleft instead of xltoright? (Ok it is very late here, but I think I know my right from left) I checked it, you must write xltoleft.

lastColumn = Sheet1.Cells(1, sheet1.Columns.Count).End(xlToleft).Column

This is the answer:

numCols = objSheet.UsedRange.Columns.count

Documentation of the UsedRange property

Result is shown in the following code as column number (8,9 etc.):

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox lastColumn

Result is shown in the following code as letter (H,I etc.):

Dim lastColumn As Long
lastColumn = Sheet1.Cells(1, Columns.Count).End(xlToLeft).Column
MsgBox Split(Sheet1.Cells(1, lastColumn).Address, "$")(1)