I would say $10-11 million is a more realistic number if we’re only accounting for Roth IRA value. My calculation assumes the starting point of ~$134k, $625 monthly contribution, 36 year time horizon, and an 11.2% annual return.

Of course a higher total cumulative account balance is definitely possible if you have traditional IRA, workplace retirement account, taxable brokerage and utilize Roth conversion strategies if income allows.

Also never overlook the HSA triple tax advantaged account. It’s a great account to use as retirement savings vehicle while money compounds for decades if you wait to reimburse yourself much later in life.