For calculating possible tax on SS benefits, do you take out the standard deduction and personal exemptions first, to lower AGI?

The goal is to arrive at a "combined income" to see if you exceed the $32K annual combined and expose 50% of the SS benefits to tax.

Example.

$20K — Business net income (after expenses)

$14K — wife's employment

$25K — my social security

$10K — her social security

AGI calculation:

$20K business + $14K employment, less $1,500 (1/2 of SS taxes paid) = $32.5K

If I can take the standard deduction and personal exemptions here ($24,850), it reduces my AGI to $7,650.

Half my social security added ($12.5K) plus 100% of her social security ($10K) totals $22.5K.

$7,650 + $22.5K = just over $30K and under the threshold of $32K.

So two questions...

1. Is this calculation correct or did I do it wrong?

2. Is her social security added to the calculation at 50%, like mine, or at 100%?

Thanks.