Quarterly Tax Payment Calculator: How to Size Each 1040-ES Payment
Quarterly taxes have a reputation for being complicated, and they are not. There are four dates, one form, and one arithmetic question: what fraction of this year's expected tax has already been paid? Everything difficult about quarterly payments comes from estimating income that has not happened yet — which is exactly the part a calculator is good at and guesswork is not.
Who actually has to pay quarterly
The rule is a single line: if you expect to owe $1,000 or more in federal tax after withholding and credits, the IRS wants the money during the year, not in April. For a self-employed person that threshold arrives quickly, because self-employment tax alone crosses $1,000 at roughly $7,100 of net profit. Most full-time 1099 workers are in scope from their first year.
The 2026 payment schedule
Payments cover uneven periods, which trips people up. Q1 covers January through March and is due April 15, 2026. Q2 covers April and May only and is due June 15, 2026. Q3 covers June through August and is due September 15, 2026. Q4 covers September through December and is due January 15, 2027. If a due date falls on a weekend or federal holiday it moves to the next business day.
How the calculator sizes each payment
It builds your annual liability first, then divides.
Step one: net profit
Expected revenue minus expected business expenses, including mileage at the 2026 rate of $0.70 per mile.
Step two: self-employment tax
15.3% of 92.35% of net profit, with the Social Security portion capped at the wage base and Medicare uncapped.
Step three: federal income tax
Applied to taxable income after the deduction for half of SE tax and the standard deduction for your filing status.
Step four: subtract and divide
Take off any withholding from a W-2 job or spouse's job, then split the remainder across the remaining quarters.
Safe harbor: the rule that makes this low-risk
You do not have to estimate perfectly. Pay at least 90% of this year's actual tax, or 100% of last year's total tax (110% if your prior-year AGI exceeded $150,000), and the IRS charges no underpayment penalty regardless of how the year turns out. For anyone with a stable prior year, the prior-year figure is the smarter target — it is a known number, not a forecast.
What the penalty actually costs
The underpayment penalty is interest, charged quarter by quarter on the shortfall from each due date until it is paid. At the current federal underpayment rate it runs near 8% annualized. On a $6,000 annual liability paid entirely in April instead of quarterly, that is roughly $250 to $350 — irritating rather than ruinous, but wholly avoidable and non-deductible.
Uneven income and the annualized method
Seasonal businesses often earn most of their income in one or two quarters. Paying a flat quarter of the annual estimate can mean overpaying early and straining cash. Form 2210 Schedule AI lets you annualize — matching each payment to income actually earned in that period. It is more paperwork, but for wedding photographers, tax preparers, and holiday-season sellers it is worth the hour.
How to pay in under five minutes
IRS Direct Pay is free, needs no account, and pulls straight from a bank account: choose Estimated Tax, Form 1040-ES, and tax year 2026. EFTPS is the alternative for scheduling all four in advance, which is the version we recommend to anyone who has ever missed a deadline. Card payments work but carry a processing fee near 2%. States have separate portals and separate forms — do not assume the federal payment covers both.
A workflow that survives a busy year
Route income into a business account. Move 25% to 30% of each deposit into a tax savings account the day it lands. Recalculate in June and September as real numbers replace estimates. Pay from the savings account on the deadline. That is the whole system, and it is the difference between quarterly taxes being routine admin and being an annual crisis.
Frequently asked questions
+How do I calculate my quarterly tax payment?
Estimate annual federal income tax plus self-employment tax on expected profit, subtract withholding, and divide the remainder by the number of remaining quarters.
+When are quarterly taxes due in 2026?
April 15, 2026, June 15, 2026, September 15, 2026, and January 15, 2027.
+What is the safe harbor for estimated taxes?
Pay 90% of this year's tax or 100% of last year's total tax — 110% if prior-year AGI exceeded $150,000 — and no underpayment penalty applies.
+What happens if I miss a quarterly payment?
Interest-style penalty accrues on the shortfall from that due date. Paying as soon as possible reduces it, so a late payment still beats no payment.
+Can I pay all my estimated tax in one quarter?
You can pay early without issue, but paying late is penalized quarter by quarter, so front-loading is safe and back-loading is not.
+Do I owe state quarterly payments too?
In most states with an income tax, yes, with their own forms and portals. States without income tax have no requirement.
About the author
Javed Niamat · Founder & Editor, GigTax
Javed Niamat founded GigTax to make self-employment tax math understandable for rideshare drivers, delivery couriers, creators and freelancers. He builds and maintains every calculator on this site and writes the guides that explain the numbers behind them.
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