ex employer traditional 401k to Roth IRA conversion and also trying to do backdoor Roth IRA. What are the Tax Implications?

Hello,

I recently quit my ex employer and have funds in both traditional 401K (55k) and Roth 401K (10K). I dont plan to move them to the new employer. Option 1 is to let it stay as is, Option 2 i am thinking of converting to a traditional IRA now and then move it immediately to a Roth IRA. I have been doing the backdoor Roth IRA for last couple of Years. My traditional IRA account has a nil balance currently and plan to do a backdoor again for current year in the month of December. Please advise how i should approach to do the conversion from 401k to Roth IRA and still continue to be able to do a backdoor Roth IRA later. What are the potential tax implications or fines that i can incur with the 401k conversion. Should i complete the 401k (Traditional)-->Traditional IRA--> Roth IRA conversion before December month, so i have a zero balance in the traditional IRA account. I understand for 401k Roth, i can move the money to Roth IRA directly without any penalty or income limits.

 

Thanks.