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The best way is to determine your quarterly estimate taxes based on your prior year tax liability.
- You might avoid underpayment penalty. Generally, most taxpayers will avoid this penalty if they owe less than $1,000 in tax after subtracting their withholdings and credits, or if they paid at least 90% of the tax for the current year, or 100% of the tax shown on the return for the prior year, whichever is smaller.So - if you know your prior year tax liability and estimated tax liability for the current year - you may determine the minimum amount of estimate taxes to avoid underpayment penalty.
If your tax liability will be more or less than in the prior year - you will correct your estimate taxes in the last payment.
Let me know if you need any help or clarification.