there are two basic rules to avoid underpayment of estimated taxes
to avoid penalties for underpayment of estimated taxes:
1) withholding and timely estimated tax payments must equal 90% of your current year's tax
or
2) withholding and timely estimated tax payments must equal 100% of the prior year's tax. this jumps to 110% of the prior year's tax if your prior year's adjusted gross income (line 11 of the 1040) is more than $150,000
$75,000 if married filing separate)
your goal is the lower of 1 or 2. since it seems you will have a significantly larger tax bill in 2024 than 2023, your goal would be the second option.
under either option, withholding is assumed to occur evenly throughout the year but if you're completing form 2210 you can use actual withholding for each period. estimates are counted for the period if made on or before their due date
