Statement Sorter | General categorizing guide | Gig driver guide | Etsy/online seller guide

Quarterly Estimated Taxes: How to Calculate Yours From a Bank Statement

A plain-English guide for freelancers, gig workers, and small-business owners who pay estimated taxes four times a year.

If you're self-employed, the IRS expects tax payments as you earn, not just once in April. Miss a quarter by too much and you can owe an underpayment penalty even if you pay everything by the filing deadline. The number every quarter comes down to the same thing: your net income so far, income minus deductible business expenses, which means the quarter's actual work is sorting a stack of bank and card transactions into categories, not doing tax math.

The four 2026 deadlines

Period coveredPayment due
Jan 1 - Mar 31April 15, 2026
Apr 1 - May 31June 15, 2026
Jun 1 - Aug 31September 15, 2026
Sep 1 - Dec 31January 15, 2027

Dates shift slightly when the 15th lands on a weekend or holiday; always confirm the exact date on the current-year IRS Form 1040-ES instructions before you pay.

What actually drives the number

Estimated tax is based on your expected net self-employment income for the year: total income minus deductible business expenses, run through self-employment tax plus your regular income tax rate. Two common approaches:

ApproachHow it works
Safe harborPay roughly 25% of last year's total tax liability each quarter (110% of last year's tax if your income was higher, per current IRS rules) - avoids a penalty even if this year's income moves around
Actual year-to-dateTotal up this year's income and expenses through the quarter's end, apply your tax rate, subtract what you've already paid - more accurate if income changed a lot, but only as good as your category totals

Either way, the actual-year-to-date approach (and sanity-checking the safe-harbor one) needs an accurate income-minus-expenses figure, and that's the part that eats an afternoon when three months of transactions are sitting unsorted in an export.

Get the number in minutes, not an afternoon

Statement Sorter takes the CSV export from your bank, PayPal, or card account and sorts every transaction into expense categories automatically, with an AI pass for anything the rules miss, so you get category totals you can hand straight to a 1040-ES worksheet or your preparer.

Skip the manual sort.

Drop in this quarter's statement, get categorized totals in under a minute. No bank login, no signup, free while in beta.

Try it on your statement

A note on accuracy

This is a general guide, not tax advice for your specific situation - safe-harbor percentages, deadline dates, and what counts as deductible can all vary by year and by state. Confirm current numbers on IRS Form 1040-ES or with a tax preparer before you pay.