What does this estimated-tax planner calculate?
The planner subtracts your expected federal withholding from the total tax estimate you enter. If the difference is positive, it divides that planning balance into four equal amounts and places them on the four dates you provide. If withholding is equal to or greater than expected tax, the displayed planning balance and installments are zero. The prior-year tax field is shown for comparison, but does not change the schedule.
For instance, if a user enters $8,000 expected tax and $2,000 expected withholding, the remaining planning balance is $6,000 and each of four equal installments is $1,500. Those are hypothetical arithmetic results, not a statement that this amount or timing satisfies federal tax rules. Use your own tax estimates and dates; the tool does not fetch tax records, market data, or IRS payment deadlines.
Why enter prior-year tax?
The prior-year amount can help you compare your own estimate with last year’s total tax while planning. Federal estimated-tax requirements can involve rules based on current-year expected tax, prior-year tax, withholding, filing circumstances, and other details. This page deliberately does not apply a safe-harbor percentage or infer which prior-year figure belongs in an official worksheet. It only displays the number you enter as context. Confirm the proper figures and tests in the current Form 1040-ES and Publication 505.
Why might four equal payments be a poor fit?
Publication 505 describes regular installments for taxpayers whose income is basically even across the year. It also explains that unequal income can call for the annualized income installment method, using income and other items through each period. Investment income can arrive unevenly: a security sale, dividend, interest payment, or other taxable event may occur in one part of the year. This simple planner does not know when you received income, how much tax withholding occurred in each period, or whether an annualized method applies.
What should I verify before paying?
Use the official IRS Form 1040-ES worksheet and Publication 505 to determine whether payments are required, the correct installment amounts and dates, and whether a special rule applies. IRS guidance notes that payment dates can shift when they fall on weekends or legal holidays. This tool does not adjust dates for those rules and does not handle fiscal tax years, farm or fishing income, amended estimates, prior overpayments, actual payment history, withholding timing, state tax, or Form 2210 penalty calculations. Consider a qualified tax professional for your situation. This educational planner is not tax or financial advice.
Primary sources checked 2026-11-03: IRS Form 1040-ES information; IRS Publication 505 (2026). Review the current IRS worksheets and instructions before relying on a payment schedule.
Frequently asked questions
Does this tell me whether I owe estimated tax?
No. It creates an equal split of the amount you enter after withholding. Use the current IRS worksheets to decide whether estimated payments are required.
Does prior-year tax set the installment amount?
No. It appears for comparison only. The tool does not calculate required annual payment or safe harbor.
Can I use uneven payment amounts?
This version divides the planning balance equally into four installments. IRS annualized-income rules can produce different required amounts; use Publication 505 and Form 2210 instructions for those calculations.
Are the dates adjusted for weekends or holidays?
No. Enter the dates you want to plan around and verify official deadlines in IRS guidance, including any weekend or holiday adjustment.