Get your taxes done using TurboTax

@TaxNoob8 the IRS considers an equal amount of withholding withheld for each period though you can use your actual withholding.  estimated tax payments only count based on the date paid so you could still have penalties for the first 3 quarters. the other options are to use the annualized income method ( page 3 of the 2210) or request abatement as previously mentioned.