Enter your numbers. We compute self-employment tax, federal and state income tax, safe harbor, and hand you four per-quarter payments lined up to the actual 2026 IRS due dates.
| Quarter | Due date | Payment |
|---|---|---|
| Q1 | April 15, 2026 | $0 |
| Q2 | June 15, 2026 | $0 |
| Q3 | September 15, 2026 | $0 |
| Q4 | January 15, 2027 | $0 |
Let's lay it out on the table, man. The US tax system is pay-as-you-go. W-2 employees pay every two weeks because their boss withholds the tax and wires it to the IRS. Freelancers do not have a boss doing that, so the IRS requires the freelancer to mail in four checks a year instead. Skip a check and a little letter arrives in April with a penalty attached.
This is the Quarterly Tax Turd. The grumpy little bureaucrat who waits in the mailroom with an IRS form in one hand and a calculator with no instructions in the other. He does not tell you the safe harbor rule. He does not tell you about Form 2210. He just mails you a penalty notice the following April and smirks when you open the envelope.
Most first-time freelancers do not even know the rule exists. They file in April, find out they owe $15,000, cut the check, and three weeks later get a second letter adding a $300 underpayment penalty. Nobody warned them. The IRS assumes you read Publication 505 cover to cover.
FigureNerd does not assume that. The calculator up top figures your tax, figures your safe harbor, and gives you four payments with the actual 2026 due dates. Pay on the dates, penalty avoided.
The IRS breaks the year into four periods, but they are not calendar quarters. Q1 covers January through March and is due April 15. Q2 covers April and May only (two months) and is due June 15. Q3 covers June, July, and August, due September 15. Q4 covers September through December, due January 15 of the following year. The uneven month counts are why people get confused.
| Quarter | Income period covered | 2026 due date | Plain English |
|---|---|---|---|
| Q1 | Jan 1 to Mar 31, 2026 | April 15, 2026 | Same day your 2025 return is due. |
| Q2 | Apr 1 to May 31, 2026 | June 15, 2026 | Short two-month window. Easy to forget. |
| Q3 | Jun 1 to Aug 31, 2026 | September 15, 2026 | Covers three months. |
| Q4 | Sep 1 to Dec 31, 2026 | January 15, 2027 | Falls in the next calendar year. |
If a due date falls on a Saturday, Sunday, or federal holiday, the deadline shifts to the next business day. April 15, 2026 lands on a Wednesday, so the Q1 due date is the standard date with no shift.
Most states that collect income tax follow the same four dates for state estimates. A handful, Iowa and Delaware among them, use a slightly different schedule. Check your state's department of revenue site before writing state checks.
Here is the piece of the tax code that actually protects you, and almost nobody learns about it until after they have already been penalized. Safe harbor. It means the IRS will not charge an underpayment penalty, period, if your withholding plus estimated payments reaches one of two thresholds.
Path one: pay at least 90 percent of your current year's total tax. Problem with this path: you do not know your current year's total tax until January. You are guessing all year. If you guess too low, the penalty hits.
Path two: pay at least 100 percent of last year's total tax (110 percent if your prior year AGI was over $150,000, or $75,000 if married filing separately). This path is the one most freelancers use, because last year's total tax is a known, fixed number sitting on line 24 of your prior 1040. Pay to that number in four equal installments and the safe harbor locks in, full stop, even if your current year income triples.
The calculator above shows both paths. The "safe harbor" line tells you the smaller of the two thresholds, because that is the number the IRS actually enforces. You can pay to either, not both.
If your total withholding plus estimates falls short of both safe harbor thresholds, the IRS charges an underpayment penalty. The penalty is calculated on Form 2210 and varies by how short you were and when the shortfall occurred during the year. Missing the Q1 payment costs more than missing Q4, because the IRS calculates interest from the due date to the payment date.
The rate floats with the short-term applicable federal rate (AFR) plus 3 percent, which has been running 7 to 8 percent annualized in recent years. For a typical freelancer who underpaid by $5,000 for a full year, the penalty runs roughly $200 to $400. For larger underpayments or longer stretches, it scales proportionally.
The IRS sends the penalty notice automatically, usually about three weeks after you file your return and settle up. You can dispute it with reasonable-cause arguments (retirement, disability, disaster, first-year filer), but default outcome is you pay.
There is also a small-balance exemption. If your total tax after withholding and refundable credits is under $1,000 for the year, no penalty regardless of estimates. And first-year filers (people with no prior-year tax return) get a pass on the 100 percent prior-year safe harbor path, because there is no prior year to reference.
Meet Dan. Web developer, 34, left his W-2 job in February 2025 to freelance full time. First year out, he billed about $120,000, landed three retainers, and felt great about the decision. He knew he would owe tax in April. He did not know he was supposed to pay it in four chunks along the way.
Dan missed Q1 (April 15, $4,200). He missed Q2 (June 15, another $4,200). He missed Q3 (September 15, another $4,200). By the time Q4 rolled around (January 15, 2026), a colleague mentioned quarterly taxes in passing and Dan Googled it. That night he discovered he was about to owe $16,800 in estimated tax across three missed quarters, plus whatever the Q4 payment should have been, plus a penalty.
He filed his 2025 return in April 2026. Total federal tax liability came out to $22,000. Withholding from his two months of W-2 in January and February covered $1,400. He wrote a check for $20,600 to settle the balance. Then, roughly four weeks later, the IRS mailed him a second notice: underpayment penalty, $487.
Here is the part that hurts. Dan's prior year (2024) total tax, from his W-2 job, was $8,200. If Dan had paid that $8,200 in four equal installments of $2,050 across 2025, he would have hit the 100 percent prior-year safe harbor, and the penalty would have been $0. He still would have owed the same $20,600 balance in April. But the $487 in penalty? Gone.
What Dan did wrong: he did not know the safe harbor rule existed. He assumed quarterly was optional and April was the real deadline. What Dan does now: sets up IRS Direct Pay, schedules four payments a year in advance, and uses the prior-year safe harbor method every year. The Quarterly Tax Turd defeated by a $2,050 automation and a 12-minute Google session.
The lesson: most underpayment penalties come from not knowing the rule, not from genuinely bad planning. Five minutes with the calculator above, four scheduled payments with IRS Direct Pay, and you never see the envelope.
If you spend 20 minutes on r/tax, r/freelance, or r/personalfinance, the same three questions repeat every quarter. Here is what the community tends to converge on, paraphrased for the FigureNerd voice.
Q: "I underestimated Q1 badly. Do I catch up in Q2 or wait until next year?"
Community consensus: catch up in Q2. Safe harbor is calculated quarter by quarter, not annually. If you pay the shortfall by the Q2 deadline, the penalty for Q2 resets and you only owe the small interest charge for the period between the Q1 deadline and the Q2 deadline, which is typically small. Waiting until April means the penalty accrues for three quarters of interest instead of one.
Q: "Do I pay quarterly if I just started freelancing in July?"
Community consensus: yes, starting with the Q3 payment due September 15. The IRS does not care that you just started. They expect you to estimate from the day your first dollar of untaxed income came in. The annualized-income method on Form 2210 is an option for people with lumpy mid-year income; it often reduces the penalty versus the default per-quarter method.
Q: "Should I just increase W-2 withholding instead of quarterly if my spouse still has a W-2?"
Community consensus: yes, and this is actually the cleanest hack. Withholding is treated as paid evenly throughout the year even if it was all withheld in December. If you can bump a spouse's W-2 withholding by filing a new W-4 with extra withholding, you can effectively "pay quarterly" via payroll and skip the estimate payments entirely. Particularly useful when you realize mid-December that you are about to miss safe harbor.
The Quarterly Tax Turd only wins when you forget. Use IRS Direct Pay, schedule all four payments now, set a calendar reminder three days before each one, and the whole problem disappears. You are not late, you are not surprised, and you are not paying the penalty.
We show our math so you can trust the number. Here is the order of operations the calculator runs, using 2026 rates and thresholds.
Where we simplify: we do not run the annualized-income method (Form 2210 Part III), which can lower penalties for people with lumpy income. We do not model Qualified Business Income (QBI) deduction, which can reduce taxable income 20 percent for most pass-through income. We do not model child tax credit, EITC, or other refundable credits. We do not model additional Medicare tax on investment income (NIIT, 3.8 percent above MAGI thresholds). If your situation is complex, run the numbers here as a sanity check, then hand the actual return to a CPA.
There is a point where a generic calculator, even a good one, is not enough. If any of these describes you, the cost of a CPA (typically $400 to $1,500 per return) pays for itself in avoided penalties and surfaced deductions.
For simple freelance or 1099 income with one state and no weirdness, the calculator above is usually within a few hundred dollars of what a CPA's projection would be.
If you expect to owe at least $1,000 in federal tax for the year after subtracting withholding and refundable credits, the IRS generally expects you to pay estimated tax in four quarterly installments. Freelancers, 1099 contractors, sole proprietors, single-member LLC owners, S-corp owners with under-withheld distributions, landlords, and anyone with significant investment income all typically fall into this rule. If you have a W-2 job with enough withholding to cover your tax bill, you can often skip quarterly entirely.
The four federal estimated tax due dates for the 2026 tax year are April 15 2026 (Q1), June 15 2026 (Q2), September 15 2026 (Q3), and January 15 2027 (Q4). The Q4 payment covers income earned between September and December 2026. If a due date falls on a weekend or holiday, the deadline shifts to the next business day. Most states follow the same schedule for state estimates.
The safe harbor rule lets you avoid the underpayment penalty if your total withholding plus estimated payments equals at least the smaller of 90 percent of your current year tax liability or 100 percent of last year's total tax. For higher earners with adjusted gross income over $150,000 ($75,000 if married filing separately), the prior-year threshold jumps to 110 percent. Paying to the prior-year number is the simplest way to lock in safe harbor because the prior-year number is a known, fixed amount.
Project your annual net self-employment income, subtract half of the self-employment tax and any above-the-line deductions (pre-tax retirement), apply the 2026 federal tax brackets to the remaining taxable income, add the full 15.3 percent self-employment tax on net earnings up to the Social Security wage base ($184,500 for 2026) plus 2.9 percent Medicare above, add state income tax, subtract any federal withholding from a W-2 or prior estimates, and divide the remainder by four. That is your per-quarter payment.
If your total withholding plus estimated payments falls below both safe harbor thresholds, the IRS charges an underpayment penalty calculated separately for each quarter on Form 2210. The current underpayment rate floats with the short-term AFR plus 3 percent (7 to 8 percent annualized in recent years). Penalty amounts are typically modest ($50 to $500 for a single missed quarter on a typical freelance income), not catastrophic, but they compound if multiple quarters are missed and interest accrues until paid.
The IRS offers three fast ways: IRS Direct Pay at irs.gov/payments (free, direct from your bank account, no account required), the EFTPS system (requires enrollment, good for recurring), or a debit or credit card via an approved payment processor (fee applies). Most freelancers use IRS Direct Pay because it is free and can be scheduled a year in advance. State payments are made through the state's department of revenue or taxation website. Keep the confirmation numbers for every payment, they flow onto your Schedule 3 at tax time.
Disclaimer. This article is for educational purposes only and does not constitute legal, tax, accounting, or financial advice. Tax situations vary by state, filing status, and individual circumstances. Consult a qualified CPA or enrolled agent before making tax decisions.