Please don’t take the following as tax advice. It’s what I did, not necessarily what others should do.

I’m filing Form 4868 for an automatic extension of time to file my tax return. But that doesn’t give me any extra time to pay any taxes owed, so I must estimate my tax liability and send that in. Specifically, I must pay at least 90% of my total tax due by April 17th in order to avoid penalties for late payment. Here’s my quick and dirty estimation method:

Estimating total taxable income. I added up all the income from our W-2s, 1099-MISCs, 1099-INT, 1099-DIV, capital gains, and other gross business receipts to get our gross income. I took out our 401(k) contributions and a ...