Estimated Quarterly Tax Calculator
↻ Updated 2026Estimate what to send the IRS each quarter on 1099 or self-employment income — combining federal income tax and self-employment tax, minus any withholding — with the four 2026 due dates.
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How to read your quarterly payment
Two taxes are stacked in that one number and only one of them scales with your bracket. On $80,000 of profit, self-employment tax is $11,304 and income tax is $7,527 — SE tax is the larger of the two, and it would still be owed if your income tax were zero. The quarterly figure is simply the total split four ways.
How your 1040-ES payment is worked out
Self-employment tax first, then income tax on what's left after half of it — that order matters, because the deductible half of SE tax reduces the income the brackets see.
The two are added, any withholding is subtracted, and the remainder is divided by four. Nothing here is a rule of thumb: it's the same arithmetic your Form 1040 will do, run forward on an estimate.
net earnings = net income × 0.9235 SE tax = 12.4% × min(net earnings, $184,500) + 2.9% × net earnings + 0.9% × (net earnings − threshold), if above taxable income = net income − (SE tax ÷ 2) − standard deduction income tax = brackets applied to taxable income total tax = income tax + SE tax quarterly = max(0, total tax − withholding) ÷ 4 2026 due dates (Form 1040-ES): Q1 Jan 1 – Mar 31 due Apr 15, 2026 Q2 Apr 1 – May 31 due Jun 15, 2026 Q3 Jun 1 – Aug 31 due Sep 15, 2026 Q4 Sep 1 – Dec 31 due Jan 15, 2027
- net income
- Expected self-employment profit for the year — revenue minus expenses — an estimate made in advance, which is the whole difficulty of this exercise
- net earnings
- 92.35% of net income — the base for SE tax — the standing adjustment for the employer's half of FICA (IRS Schedule SE)
- SE tax ÷ 2
- The deductible half, removed before income tax is calculated — an above-the-line adjustment; it reduces income tax only, never SE tax itself
- standard deduction
- $16,100 single, $32,200 married filing jointly for 2026 — Rev. Proc. 2025-32; the calculator always applies it and never itemises
- withholding
- Federal tax already withheld from a W-2 job or prior payments — a credit against the annual total, spread across all four payments
- quarterly
- What to send with each Form 1040-ES voucher — floored at zero — withholding above your total tax shows $0, not a refund
The quarters aren't quarters. Q1 covers three months, Q2 covers two, Q3 covers three and Q4 covers four — an artefact of the due dates being pinned near the middle of the month following each period. Dividing by four is correct for income that arrives steadily and wrong for income that doesn't: a consultant who earns everything in Q4 and pays a quarter in April has overpaid early, while one who earns everything in Q1 and pays a quarter each time has underpaid the first period and may owe a penalty despite settling the year in full.
The remedy for lumpy income is the annualised income installment method on Form 2210, Schedule AI, which sizes each payment to what you actually earned in that period. This calculator doesn't implement it. What it does implement is the plain even split — the right answer for steady income and the starting point for everything else. For the SE tax component alone, the self-employment tax calculator shows the full breakdown.
Worked examples
Example: $80,000 of self-employment profit, no withholding
The calculator's defaults. A single filer whose freelance business expects $80,000 of net income and who has no W-2 job.
| Net self-employment incomeafter business expenses | $80,000 |
| Net earnings (× 92.35%)the SE tax base | $73,880 |
| Self-employment tax$9,161 Social Security + $2,143 Medicare | $11,304 |
| Less deductible half of SE taxreduces income, not SE tax | − $5,652 |
| Less standard deduction2026 single | − $16,100 |
| Taxable incomewhat the brackets see | $58,248 |
| Federal income taxacross the 10, 12 and 22% brackets | $7,527 |
| Total annual tax$7,527 income tax + $11,304 SE tax | $18,830 |
| Each quarterly payment$18,830 ÷ 4 | $4,708 |
| Effective rate on profitcombined federal | 23.5% |
$4,708 four times a year. Note which tax is bigger: SE tax at $11,304 is 60% of the total, and it's charged at a flat 14.13% of profit whether you earn $30,000 or $150,000. Income tax is the progressive part — at $150,000 of profit the total climbs to $43,385 and the quarterly payment to $10,846, because income tax has reached the 24% bracket while SE tax has not changed its shape at all.
Example: the same $80,000 with $6,000 already withheld
Same freelancer, but a part-time W-2 job — or a spouse's paycheck under married filing jointly — has already sent $6,000 to the IRS.
| Total annual taxunchanged — withholding doesn't alter the tax | $18,830 |
| Less tax already withhelda credit against the whole year | − $6,000 |
| Remaining to payspread across four vouchers | $12,830 |
| Each quarterly payment$12,830 ÷ 4 | $3,208 |
| Change vs the first exampleper quarter — exactly $6,000 ÷ 4 | −$1,500 |
The tax didn't move; only the schedule did. Every $1,000 of withholding takes $250 off each voucher. Withholding also carries a timing advantage no estimated payment has — the IRS treats tax withheld at any point in the year as though it were paid evenly across all four periods, so December withholding can cure an April shortfall. An estimated payment made in December cures nothing that was due in April.
Frequently asked questions
What happens if I miss a quarterly estimated tax payment?
The IRS charges an underpayment penalty computed period by period, not as a single year-end judgement. It works like interest on the shortfall for the days it went unpaid, so a payment made late is cheaper than one never made, and paying extra in September does not erase an April shortfall — each period is tested on its own.
This is the part that surprises people: you can settle your whole tax bill in full at filing, owe nothing, and still be charged a penalty for having paid it late. There's a de minimis escape — no penalty if you owe less than $1,000 after withholding and credits — and the safe harbours below are the reliable way out. Relief for reasonable cause is requested on Form 2210 (IRS, Pay As You Go, So You Won't Owe).
What is the safe harbor rule for estimated taxes?
It's the deal that makes estimated tax survivable: pay enough on time and the IRS won't penalise you no matter how the year turns out. You're safe if you pay at least 90% of the current year's tax, or 100% of last year's total tax — 110% if your prior-year AGI exceeded $150,000 ($75,000 married filing separately). You're also safe if you owe under $1,000 after withholding.
The prior-year test is the valuable one, because last year's tax is a number you already know. Estimating the current year is guesswork; matching last year is arithmetic. A freelancer whose income doubles can pay 100% of last year's tax across four vouchers, owe a large balance in April, and owe no penalty on any of it — the safe harbour protects against the penalty, not against the tax (IRS Publication 505).
When are 2026 quarterly estimated tax payments due?
April 15 2026, June 15 2026, September 15 2026 and January 15 2027 — the four dates this calculator lists against each voucher. A due date falling on a weekend or legal holiday moves to the next business day.
The periods behind those dates are not equal, which is the detail that trips people up. Q1 covers January through March, Q2 covers only April and May, Q3 covers June through August, and Q4 covers September through December. Two months of income are due in June and four months in January. One useful escape: file your 2026 return and pay in full by February 1 2027 and the January installment is not required at all.
Do I have to pay quarterly taxes my first year self-employed?
The trigger is expected tax, not experience: estimated payments are required if you expect to owe $1,000 or more after withholding and credits. On this calculator's defaults, $80,000 of profit produces $18,830 of tax — far past the threshold, and none of it withheld by anyone.
First years have a specific quirk worth knowing. The prior-year safe harbour is 100% of last year's tax, and if last year you were a student or an employee whose withholding covered everything, that figure may be small — or zero, in which case the safe harbour requires nothing. You'd still owe the full tax at filing; you simply wouldn't owe a penalty for not having prepaid it. The $400 net-earnings threshold is separate and governs whether you owe SE tax at all, not whether you must prepay it.
Where this quarterly estimate diverges from Form 1040-ES
The tax arithmetic matches a 1040 for a simple single-income freelancer. The scheduling and the deductions are where it simplifies.
- Four equal payments, four unequal periods — The total is divided by four regardless of when you earn it. For lumpy income the annualised income installment method on Form 2210 Schedule AI sizes each payment to the period's actual earnings — this calculator doesn't implement it, so a seasonal business paying these figures on this schedule can still incur a penalty.
- No safe-harbour calculation — The page computes 100% of estimated current-year tax and never looks at your prior year. Since the 100%/110% prior-year test is the safe harbour most freelancers actually use, the figure here may be considerably more than you're required to pay to stay penalty-free.
- No QBI deduction — The §199A qualified business income deduction can remove up to a fifth of qualifying business income from taxable income. It isn't modelled, so for an eligible sole proprietor the income tax component — and the quarterly figure — is overstated.
- No credits, no itemising, no state — Standard deduction only, no credits of any kind, and federal only. Most states with an income tax run their own estimated payment schedule with its own vouchers and its own penalty.
- The wage base ignores your W-2 wages — The withholding field credits tax paid, but the job that produced it also used up part of your $184,500 Social Security wage base — and the SE calculation here doesn't know. For anyone whose wages plus profit approach the base, this overstates the Social Security portion.
Rates, brackets and limits here are checked against primary sources. If a number still looks off, email support@realmoneyiq.com and we'll review and fix it.
RealMoneyIQ provides free educational calculators, not financial, tax, investment or legal advice. Results are estimates based on the assumptions you enter and publicly published rates; your actual outcome will differ. Always confirm decisions with a licensed professional who knows your full situation.