Turbotax is saying my W2 needed to be corrected but my employer said turbotax is calculating social security wrong and my w2 is fine. How can I proceed with current w2?

Multiply the amount in box 3 of your W-2 by 6.2%.  If the amount of taxes withheld in box 4 is a few cents greater then 6.2%, remove the cents in box 4.

Social Security is 6.2%.  Double check your entries to be sure that everything including wages is entered correctly.  Also, double check the math on the numbers to be sure that 6.2% was withheld for social security. You will use box 3 of your W-2 for this calculation. 

Do you only have one job?  Did you make over $168,600?  If you did, then the amount over that is not subject to social security.  So that would be another reason that it could be saying you are due a refund. 

You can still file your return even if TurboTax is saying you are due a refund for SS as this is not claimed through your tax return, instead this is handled separately by getting a refund from your employer. 

First of all try leaving the cents off box 4.
Check boxes 3 & 4 on your W2. Box 4 should be 6.2% of box 3 up to a max of $10,453.20. So take the amount in box 3 and multiply it by .062. If box 4 is more than that you need to get a corrected W2 from your employer. But also go back and double check your W2 entries, you may have entered box 3 & 4 wrong. A lot of people who have asked this found they did enter an amount wrong.

Or check W2 box 12. You may have entered Code A by mistake.

A sure way to fix this is to delete the W2 and re-enter it. That may clear something out. Or post back with the amounts in boxes 3&4.