Formula to change Phone Number format

[pete5440]

I have a large list of 10 digit phone numbers currently formatted as
1234567890. I would like to change them so area code and prefix is separated
by hyphen 123-456-7890. Is there a relatively simple way to do this with a
formula? Would having some of the numbers already changed to my desired
format affect how the formula runs?

 

[Sean Timmons]

Highlight column.. format Cells..

Custom

000-000-0000

Course, if you use Special, there is one for phone number that uses (201)
instead, so your choice.

 

[Kevin B]

Insert a helper column and enter the following formula, replacing cell A1 in
the example with the first cell containing your phone numbers:

=LEFT(A1,3)&"-"&MID(A1,4,3)&"-"&RIGHT(A1,4)

Copy down the help column.

Copy all the formulas in the helper column and move the cell pointer to the
first cell containing your original phone numbers. Right click on the cell,
select PASTE SPECIAL, click the VALUES option button and click the OK command
button to return to the worksheet.

Delete the helper column when done.

 

[John C]

Did you catch the part where the OP said some numbers are already formatted
as xxx-xxx-xxxx?

 

[Sean Timmons]

And oh, having -'s in some wouldn't make a difference unless they aren't set
the same as your desired cells. If so, just do a Find - then Replace with
nothing

 

[Kevin B]

The format modifies the appearance and I took it to mean that he wanted to
convert the current values to include the "-" at position 4 & 8. Otherwise
you can just use a format mask of ###-###-#### if all you want to do is
change the way the numbers appear.

I interpreted the question to mean a conversion and not a format change.

Thanks...

 

[John C]

You misunderstand. I agree with your formula, but you don't check if the cell
is already in the format of 123-456-7890. Your formula is:
=LEFT(A1,3)&"-"&MID(A1,4,3)&"-"&RIGHT(A1,4)
which would convert the above formula to:
123--45-7890
Assuming the OP only has 2 possibilities in the column, 1234567890 and
123-456-7890, I would modify your formula thusly:
=IF(LEN(A1)<>10,A1,LEFT(A1,3)&"-"&MID(A1,4,3)&"-"&RIGHT(A1,4))