As I wrote in my OP I have small distributions from an IRA. I don't run a business or have an accountant to figure out quarterly taxes. I guess I'll run turbotax scenarios to see what I should pay.
It doesn’t matter where the income comes from. If you have taxable income from any source you have to estimate the tax you owe and pay it quarterly. Maybe you should just let your IRA withhold the tax for you. You pay it either way.