where do i add social security income

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

Social security income is reported on form SSA-1099 which should be sent to you by Social Security in January 2025.

This is how you enter this form SSA-1099 in your tax return:

1. In TurboTax Online, open your return
2. Click on Search (magnifying glass icon) at the top right of your screen
3. In the Search box, enter form SSA-1099 and click Enter
4. In the search result box, click on Jump to form SSA-1099
5. TurboTax will take you directly to the section where you can start entering your form SSA-1099.

Also FYI - 

Up to 85% of Social Security becomes taxable when all your other income plus 1/2 your social security, reaches:

Married Filing Jointly: $32,000

Single or head of household: $25,000

Married Filing Separately: 0

To see the Social Security Benefits Calculation Worksheet in Turbo Tax Online version you would have to save your return with all the worksheets to your computer. Or if you are using the Desktop CD/Download Software you can switch to Forms Mode (click Forms in the upper right) and click on SS in the list on the right side.