Percent Error When Known = 0

[timstring]

I am trying to calculate the percent error where my known quantity is 0.

Percent error = (Calculated - Known) / Known

But, how do I calculate this:

Percent error = (Calculated - 0) / 0 ?

Excel is going to return a Div/0 error. How do I compensate for the 0 denominator? Telling Excel simply to ignore the problem is NOT an option.

[avk]

"e9"

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[timstring]

As I said, ignoring the error, which your formula does, is not an option!!

[Pete_UK]

What do you want to happen if known is zero? You could take this approach:

=IF(known <> 0, (Calculated - Known) / Known, your_preferred_action)

Hope this helps.

Pete

[MrShorty]

Unless you are Chuck Norris, you cannot divide by 0. Percent error has not meaning when the reference value is 0. You, the programmer, or those asking you to solve the problem, will need to decide what "percent" error means when the reference value is 0, then use some kind of IF() function like Pete suggests.