Did you do the math or are you questioning how the worksheet did the math?

Example"

Trad IRA has $14,000 in it already, pre-tax (deducted) contributions + earnings. The client wants to Backdoor, so they contribute $7,000 post tax (will not deduct). They intend to convert $7,000. It's never the same money. It's just the same amount as the contribution. This won't be a Backdoor. Now it's a pro rata conversion. Their post-tax contribution is Basis.

All Trad IRA, SEP IRA and SIMPLE IRA balances are aggregated.

$14,000 + $7,000 = $21,000

$7,000 divided by $21,000 = 1/3 of every dollar contributed is considered to be from Basis and not taxable. 2/3 is taxable.

$2,331 not taxable.

$4,669 taxable as ordinary income.

And for the future, the original $7,000 basis is reduced by the $2,331, leaving $4,669 Basis for next conversion or distribution.