Our MAGI is above the $44000 limit, so 85% of our SS income is taxable. Does TurboTax online automatically do this calculation?

Yes, TurboTax calculates the taxable portion of your Social Security benefits based on the worksheets in IRS Publication 915, Social Security and Equivalent Railroad Retirement Benefits

To enter Social Security benefits reported on form SSA-1099

• Click on Federal Taxes (Personal using Home and Business)
• Click on Wages and Income (Personal Income using Home and Business)
• Click on I'll choose what I work on (if shown)
• Scroll down to Retirement Plans and Social Security
• On Social Security (SSA-1099, RRB-1099), click the start or update button

Or enter ssa-1099 in the Search box located in the upper right of the program screen.  Click on Jump to ssa-1099