IRA, Roth, 401K - Help with conversion

万能的投坛， Help with Roth conversion

I have 401k from the previous employer, and tranditional IRA (after tax contribution), and I am considering Roth IRA conversion.

401K is before tax contribution, and traditional IRA is after tax contribution.

Hypothetically, if I have 100K in 401K, and 100K in traditional IRA for after tax contribution, but no gain since I invested.

Now I am converting to Roth IRA.

(1) If I don't roll over 401K to IRA, then 100K from traditional IRA to Roth IRA.  I don't need to pay tax this year
(2) If I convert 401K to IRA, I convert 100K to Roth, Roth would take 50K from the traditional IRA portion, and take 50K from the 401K portion (after convertion to IRA).  Then I need to pay tax on 50K (income) this year.

Am I right?

So the correct way is to go follow with (1)