Freelancers and independent contractors don't get taxes withheld from every payment the way a W-2 employee does, so the IRS expects you to pay estimated tax four times a year instead of once at filing time. This calculator turns your expected annual net profit and your own effective tax rate estimate into a quarterly payment schedule, and adjusts it for anything you've already sent the IRS this year — so you can see the number without doing the arithmetic by hand every time your income projection changes.
How it works
You supply three numbers: your expected annual net profit, an effective tax rate (your own estimate of combined federal income tax plus self-employment tax on that profit), and how much you've already paid toward this year's taxes. The calculator multiplies profit by the rate to get your estimated annual tax, divides that by 4 for the baseline per-quarter figure, and separately works out what's left to pay — your annual estimate minus what you've already paid, spread evenly across 4 payments. If you've already paid more than the estimate, the remaining figure floors at zero instead of going negative.
This tool does not compute your effective tax rate for you. It takes the rate you enter at face value, so the quality of the output depends entirely on the quality of that estimate. If you want a rigorous self-employment tax figure to build the rate from, use this site's self-employment tax calculator for that piece and layer an income-tax estimate on top.
Worked example
Say your expected annual net profit is $60,000 and you estimate your effective tax rate — income tax plus self-employment tax combined — at 25%.
- Estimated annual tax: $60,000 × 25% = $15,000
- Per quarter: $15,000 ÷ 4 = $3,750
- If you haven't paid anything yet this year, the remaining-per-quarter figure is also $3,750 — the full annual estimate, spread evenly across all four payments.
Now say you'd already sent the IRS $6,000 against an $80,000 profit taxed at 30% (a $24,000 annual estimate): the remaining balance is $24,000 − $6,000 = $18,000, spread over 4 payments for $4,500 per quarter — lower than the flat per-quarter figure, because part of the year's bill is already covered.
How to interpret your result
The per-quarter figure is what you'd owe each period if you paid evenly across the whole year with nothing paid so far — useful for planning from January 1. The remaining-per-quarter figure is the more practical one mid-year: it accounts for whatever you've already sent in and spreads only the shortfall across the payments left. Note that this calculator always divides the remaining balance by 4, not by however many quarters are actually left in the year — it's a simplified, predictable planning number, not a precise catch-up schedule for a quarter you've already missed.
Treat every figure here as a planning estimate built from the tax rate you supplied, not an authoritative tax computation. This tool doesn't calculate your actual liability, doesn't know your deductions or credits, and isn't a substitute for a real return or a tax professional.
Methodology & sources
The IRS expects estimated tax payments four times a year, on or around these dates — always confirm the exact date for the current year, since weekends and holidays shift them:
- Quarter 1: on or around April 15
- Quarter 2: on or around June 15
- Quarter 3: on or around September 15
- Quarter 4: on or around January 15 of the following year
The formula is estimatedAnnualTax = expectedAnnualNetProfit × effectiveTaxRatePercent ÷ 100, perQuarter = estimatedAnnualTax ÷ 4, and remainingPerQuarter = max(0, estimatedAnnualTax − alreadyPaid) ÷ 4, all derived from the unrounded annual figure before rounding to the cent.
This calculator does not apply the IRS safe-harbor rules, which can reduce what you owe by quarter if you pay at least 90% of this year's tax or 100% (110% for higher incomes) of last year's — see the IRS's own Estimated Taxes page for the current-year due dates, safe-harbor thresholds, and payment methods. This tool covers US federal estimated tax only — not state estimated tax, and not a substitute for tax advice.