Use the ISERROR method the example below returns 0 if the
formula calcuates an error.

=IF(ISERROR(A4/B4),0,A4/B4)

HTH
-----Original Message-----
Hello,

I have a spreadsheet that has named columns of data.

Column A (ReadDate) contains dates

Column B (LocationID) contains data (sample point ID's
e.g. 0001,
0002, 0003 etc)

Column C (Methane) contains data

The columns have autofilter, so for example I could
select sample
point 0003 in column B (LocationID).

On a separate worksheet I created a foruma using SUBTOTAL
to
calculate MIN, MAX, MEAN etc. An example of the formula
is:

=SUBTOTAL(5,Methane)

which returns the minimum value from the methane column,
or the
minimum methane value for a sample point if a specific
sample point
had been selected in column B.

The formula worksfine, except if there is a #N/A value in
the methane
column. The formula then returns a #N/A error.

My question is - how do I get the SUBTOTAL formula to
ignore the #N/A
in the Methane column and do what it is supposed to do?
I could
remove the #N/A from the methane column, but I need it
there from
charting purposes.

Hope someone can help....

thanks

Michael
.