I'm just going by what firecalc says. I don't count your house as an asset, but emergency if you need to sell it and use the money. So you effectively have $2.4mil to draw from. Firecalc only has data for 49 years, so that's the max you want to put in for the number of years you need your money to last. But historical data does not guarantee future returns even though most people here believe otherwise. Firecalc is a little optimistic, so with the $60k, I add in another $10k to it to be safe, so now it's $70k, plus you will have $6k to pay taxes, plus whatever your wife brings in to pay taxes and other expenses.
That's just my opinion, and I already know most people here will disagree. Go ask in Bogleheads board, you will get very different answers there than here.
Ok, I think your response comes from a combination of a misreading of the OP's data as well as a misunderstanding of how FireCalc and other simulators works. Much has been covered by other posters, but a few points I'd highlight
1) including wife's wages, the OP needs $30k to meet his $80k projection not $60k as stated.
2) adding "$10k just to be safe" is a rather large and
annual increase to a budget. I could understand wanting to hold a large "ER fund" (though I wouldnt do it) - but as a single expense, not in perpetuity.
3) Firecalc has over 100 years of data, not 49. Sample sizes decrease as you increase the period (time), but one method aroudn this is to "bootstrap' the data. In essence, bootstrapping is taking the results from one simulation and 'feeding' it back to see how those ending values would work going forward. It has its own pitfalls but can be very powerful when used correctly. You can even eyeball this by looking at how many periods after 30 years results in less funds. If you have more money after 30 years than you started with, than the chances that it will succeed the next 30 years are by definition higher.
4) I cannot understand where you got an additional $6k in taxes.
5) the OP's expenses are projected to decrease substantially, not increase, as large items like childcare disappear from his budget
6) the OP has SS in 27 years.
Just thought I'd throw one last thing out there - as one of many calculations, I like to just see how many years a person's portfolio would last with 0% real return. That's a pretty pessimistic projection. In the OP's case, it would be 48 years with no further spending reduction, which is slightly greater than his average life expectancy.
That's my analysis and reaction - feel free to make counter-arguments; that's how we learn here.