In VBA how a create a 'log' calculation?

New Contributor

Hi, so I want to create a function in excel VBA that is it: '= 1.16650 - 0.07063 log (CX + SI+ SB)'


But I don't know how to make 'log' work, because I can't simply digit 'log', it will not allow, it will say 'it was expected: end of instruction' 


Sorry about my English, not my first language.

4 Replies


In VBA, you have to specify multiplication explicitly by using *:


... = 1.1665 - 0.07063 * Log(CX + SI + SB)

Hi, thanks for the advising. In fact it work but the final result get wrong no matter what I do, I tried to specify by parentheses the order of the calcule but still didn't work properly.

best response confirmed by allyreckerman (Microsoft)


Keep in mind that the Log function in VBA is the natural logarithm (base e = 2.7172...). It corresponds to the worksheet function LN, not to the worksheet function LOG (base 10).

If you need to use the 10-based logarithm, use


... = 1.1665 - 0.07063 * Log(CX + SI + SB) / Log(10)

Yes, thank you.