Finance category
Mortgage, loan, investing, tax, and money calculators.
Quarterly Estimated Tax Calculator
Plan quarterly estimated tax payments for self-employment, 1099, and investment income. Includes federal, SE tax, state, and the prior-year safe harbor.
~14.13% on Schedule C net
W-2 withholding to date
Quarterly estimated payment
$7,700
Q1, Q2, Q3, Q4 each
Projected total tax
$62,539
federal + SE + state
Safe harbor (110% prior-year)
$30,800
Net required (after withholding)
$30,800
When estimates are due
Federal Q1: April 15. Q2: June 15. Q3: September 15. Q4: January 15 of following year. State quarterly schedules usually align with federal. Pay by EFTPS (free) or Direct Pay; certified mail if writing checks.
Safe harbor: pay either 90% of current year tax OR 100% of prior year (110% if prior-year AGI > $150k) — whichever is less — to avoid the underpayment penalty even if you owe more at filing.
How to Use
- Enter projected annual income (AGI for self-employed planning).
- Enter your marginal federal rate (use bracket calculator if unsure).
- Enter your SE tax effective rate (~14.13% on Schedule C net).
- Enter your state rate (use 0 if no state income tax).
- Enter any W-2 withholding already in place and prior-year total tax for safe harbor.
- Read the per-quarter payment.
Frequently Asked Questions
What's the safe harbor rule?
Pay either 90% of current-year tax OR 100% of last year's total tax (110% if prior AGI > $150k) to avoid the underpayment penalty — even if you actually owe more at filing.
When are quarterly estimates due?
Federal: April 15, June 15, September 15, and January 15 of the following year. State deadlines usually align. Mark these on the calendar — missed payments trigger penalties even if total tax is paid by April 15.
How do I pay?
EFTPS (free, requires enrollment), IRS Direct Pay (free, no enrollment), or check by mail with Form 1040-ES. State payments use the state's own portal or coupon. EFTPS lets you schedule all four quarters at once.
What if income is uneven across the year?
Use the annualized income installment method (Form 2210, Schedule AI) — pay based on actual income earned each quarter rather than splitting evenly. Useful for seasonal businesses or one-time large income events.
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Salary Calculator
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