You have the wrong formula. Here is the correct one:

C = ((1.313454 - (0.132674*F) + (0.00205779 * F^2) - (0.000002627634 * F^2)))

Where F = Temperature in degrees Fahrenheit.

C = Correction

So,

CG = C + (SG * 0.001)

Where,

CG = Specific Gravity corrected for temperature

C = Correction from above forumla

SG = Specific Gravity before temperature correction.

Here it is for everone using Degrees Centigrade:

C = ((1.313454 - (0.132674 * ((C * 1.8) + 32)) + (0.00205779 * (((C * 1.8) + 32))^2)) - (0.111112627634 * (((C * 1.8) + 32))^3)))

Then continue with the formula above formula for CG

**If you would like to use Excel for this, do the following:**
Degrees F calculation

1) Use Cell B3 as your temperature (F) input.

2) Use Cell B5 as your SG input

3) Paste the following into Cell B7:

=1.313454 - (0.132674*B3) +( 0.002057793*(B3^2)) - (0.000002627634*(B3^3))

Paste the following into Cell B9:

=B5+(B7*0.001)

Cell B9 will contain your temperature corrected SG

For people using degrees centigrade, change the formula pasted into Cell B7 to the following:

=1.313454-(0.132674*((B3*1.8)+32))+(0.002057793*(((B3*1.8)+3 2)^2))-(0.000002627634*(((B3*1.8)+32)^3))

I'm sure that I could have reduced the formula down to something "prettier", but I really didn't feel like wasting time doing that. Besides, isn't that what's so nice about using Excel.

Cheers!

Disclaimer = It is possible that I made a transposition error when transferring this from Excel, so please check the Excel results against a table before using it.