@elgato81 you can make this simpler.
1) Take Line 24 of form 1040 on your 2024 tax return. That is your tax liability.
2) and subtract Line 25d. That is your withholdings.
divide the result by 4. All things being the same in 2025 as they were in 2024, THAT will cover the Amount Due if you pay that amount quarterly.
HOWEVER, the problem is the payments are due April 14, 2025; June 15, 2025; Sept 15, 2025 and January 15, 2026. The first two payments are already past due and will drive an under payment penalty comes next April. Best to make those first two payments TODAY which will cut off the underpayment penalties.
