Where did you get 50%? You do add 50% of SS to your other income just to calculate how much it taxable. The taxable amount can be between 0-85%.
The taxable amount of Social Security is a range.
For Single between $25,000 and $34,000, you may have to pay income tax on up to 50 percent of your benefits. For more than $34,000, up to 85 percent of your benefits may be taxable.
For Joint between $32,000 and $44,000, you may have to pay income tax on up to 50 percent of your benefits. For more than $44,000, up to 85 percent of your benefits may be taxable.
See,
Benefits Planner | Income Taxes And Your Social Security Benefit | SSA
Were you trying to use the worksheet on the back of your SSA-1099 or Notice 703? You should not use the worksheet on the back of the SSA-1099. It can be complicated to figure out even though it looks simple. Turbo Tax figures it all out for you.
When you enter 1/2 of your ss on line B it is not being subtracted from anything. It is being ADDED to ALL your other income to see if any of the ss will be taxable to you.
