Quarterly Estimated Tax Calculator (Safe Harbor 2026)

A freelancer with $60,000 of annual net self-employment profit at a 22% income-tax rate owes about $21,678 for the year — $5,419 per quarter — split between $8,478 of self-employment tax and $13,200 of income tax. Enter your profit, your rate, and what you have already paid this year; the calculator below turns the annual figure into four quarterly payments and shows exactly what is left to pay.

Figures checked against 2026 IRS limits · Reviewed September 2026

How the quarterly math works

Employees settle their tax every paycheck through withholding. Freelancers get four deadlines instead — April 15, June 15, September 15, and January 15 — and the IRS estimated tax rules require payments once you expect to owe $1,000 or more for the year after withholding and credits. This calculator builds the annual bill from its two layers, then divides by four. Self-employment tax is 15.3% (12.4% Social Security plus 2.9% Medicare) applied to 92.35% of your net profit, and it starts once net earnings reach $400 for the year. Income tax is your net profit times the rate you enter — use your effective rate on the freelance income if you know it, or your marginal bracket as a conservative stand-in. The paid-to-date field then subtracts whatever you have already sent the IRS, so mid-year you see the remaining balance rather than the January number.

Formula: quarterly payment = (net profit × 0.9235 × 15.3% + net profit × income-tax rate) ÷ 4; remaining balance = annual total − estimated tax paid year-to-date.

OutputWhat it meansAt the defaults
Quarterly paymentOne-fourth of the estimated annual bill — the check to write each deadline$5,419.43
Annual totalSelf-employment tax plus income tax for the full year$21,677.73
SE-tax portion15.3% on 92.35% of net profit; owed from the first $400 of net earnings$8,477.73
Income-tax portionNet profit at the rate you entered$13,200.00
Remaining after YTD paymentsAnnual total minus estimated tax already paid this year$21,677.73

Worked example: $60,000 of profit at a 22% rate

The defaults describe a full-time freelancer with no other household income and no state income tax. First the self-employment layer: $60,000 × 0.9235 = $55,410 of taxable net earnings, then $55,410 × 15.3% = $8,477.73. Next the income layer: $60,000 × 22% = $13,200. The annual total is $8,477.73 + $13,200 = $21,677.73, which is 36.1% of net profit — the honest number behind the folk advice to "just save 30%." Divided into four equal installments, each quarterly payment is $21,677.73 ÷ 4 = $5,419.43. With nothing paid yet this year the remaining balance is the full $21,677.73; enter $10,000 already paid and the calculator shows $11,677.73 still to send across the deadlines that remain.

The safe-harbor note: what avoids the penalty

Computing the bill is only half the job; paying enough of it on time is the other half. You generally avoid the underpayment penalty by paying the smaller of 90% of the current year's tax or 100% of the prior year's tax — 110% of the prior year's tax if your prior-year adjusted gross income was above $150,000 — once you expect to owe $1,000 or more. If last year's income was stable, paying 100% of last year's bill in four chunks is the stress-free path even if this year turns out better. One thing the safe harbor does not do is pay your tax: it protects you from the penalty, not from the bill, and any balance beyond what you prepaid is still due with the return. The full schedule, the uneven quarter lengths, and the W-4 withholding trick for mixed-income households are in our quarterly estimated taxes guide.

Safe-harbor voucher math: a $10,000 prior year

Take a freelancer whose prior-year total tax was $10,000 with prior-year AGI under $150,000, expecting $15,000 of tax this year. Formula: voucher = min(0.90 × current-year tax, prior-year tax × 1.10 if AGI over $150,000 else × 1.00) ÷ 4. Here that is min(0.90 × $15,000 = $13,500, $10,000 × 1.00 = $10,000) = $10,000 for the year, or $2,500 per voucher — even though the actual bill will be $5,000 higher, the penalty is avoided and the $5,000 balance simply comes due with the return.

Common quarterly-tax mistakes

Four errors cause most estimated-tax trouble, and each one is avoidable:

For 2026, the four voucher deadlines are:

PaymentDue date
Q1 2026April 15, 2026
Q2 2026June 15, 2026
Q3 2026September 15, 2026
Q4 2026January 15, 2027

The January 15, 2027 payment is 2026 money, not 2027 money — it covers the final months of 2026, which is exactly why the first mistake above is so common.

Limitations of this estimate

This is a federal-only planning figure, not a filed return. It does not include state income tax, which you must add on top wherever your state charges it. It does not adjust for the qualified business income deduction (up to 20% of qualified business income), retirement contributions, the premium tax credit, or any other above-the-line item — each of which shrinks the income-tax layer. It assumes level income across four equal quarters; if your earnings are lumpy, the Form 1040-ES annualized income worksheet lets you size each payment to the quarter it covers instead. And the income-tax rate you enter is doing real work in the result: an effective rate understates the marginal cost of the next dollar, a marginal bracket overstates a low year, so re-run the calculator whenever a contract changes size rather than trusting January's number in October.

See also

For the deadlines, the penalty mechanics, and a safe-harbor worked example on different numbers, read the quarterly estimated taxes guide. To turn this annual figure into a percentage you move on the day each invoice clears, use the tax set-aside calculator. If you started from gross 1099 billings rather than net profit, the 1099 tax calculator walks from gross to net first. Estimate only — for education, not tax advice; confirm your figures with IRS Publication 1040-ES or a tax professional.

Every figure above is hand-checked: the worked example was recomputed independently of the calculator code, and tax figures track 2026 IRS limits. How we check every page.

Frequently Asked Questions

How much do I pay each quarter?

One-fourth of your estimated annual tax. At the defaults — $60,000 of net self-employment profit at a 22% income-tax rate — the annual total is $21,677.73 ($8,477.73 of self-employment tax plus $13,200 of income tax), so each quarterly payment is $5,419.43. If you have already paid estimated tax this year, subtract it: enter the amount in the paid-to-date field and the calculator shows the remaining balance — for example, $10,000 paid leaves $11,677.73 still to pay.

What is the safe harbor that avoids an underpayment penalty?

You generally avoid the underpayment penalty by paying the smaller of 90% of the current year's tax or 100% of the prior year's tax — 110% of the prior year's tax if your prior-year adjusted gross income was above $150,000 — once you expect to owe $1,000 or more after withholding and credits. The safe harbor protects you from the penalty, not from the bill: any balance beyond what you prepaid is still due with your return.

Does this calculator include state income tax?

No — the estimate is federal only: 15.3% self-employment tax on 92.35% of net profit plus income tax at the rate you enter. If your state charges income tax, add that rate on top of the federal figure; freelancers in high-tax states often set aside several extra percentage points per payment.

My income is uneven — should I still pay four equal quarters?

Not necessarily. Equal quarters are the default, not a requirement: the IRS Form 1040-ES annualized income worksheet lets you size each payment to the income actually earned in that period, so a quiet spring followed by a big autumn contract does not make your spring payments late. Recompute your percentage whenever a contract changes size and move the difference into your tax account the week the invoice clears.

Where do I actually send quarterly payments?

Through IRS Direct Pay, which pulls the payment from your bank account for free and returns a confirmation number — store it with that quarter's records. Tag every payment with the tax year it applies to, since payments default to the current year and January payments often belong to the prior year, and never skip a quarter just because that quarter's invoices were small.

When are quarterly estimated taxes due in 2026?

April 15, June 15, and September 15 of 2026, plus January 15, 2027 for the final quarter of 2026 — the January payment closes the prior tax year, so tag it as 2026 money. Pay online via IRS Direct Pay and keep the confirmation number with that quarter's records.