How much do I need to retire? Do I have enough?
I won't reinvent the wheel on this one.
Spending in retirement
Unsurprisingly, this is really hard to estimate, but Fidelity has guidance on this topic.
Will my portfolio cover my expenses?
FIRECalc does a phenomenal job. It relies on three inputs (anticipated annual spending in retirement, portfolio size, and expected years of retirement) and tests the likelihood your portfolio would've "made it to the end" by using historic data since 1871.