Quarterly Tax Calculator 2026

You generally must pay quarterly estimated taxes if you expect to owe at least $1,000 in federal taxes after withholding and credits for the year, and if your withholding and credits cover less than 90% of your current year tax or less than 100% of your prior year tax. This typically applies to self-employed workers, freelancers, independent contractors, sole proprietors, and anyone with significant income not subject to withholding (investment income, rental income, etc.).

The 2026 federal estimated tax payment due dates are: Q1 (income Jan–Mar) due April 15, 2026; Q2 (income Apr–May) due June 16, 2026; Q3 (income Jun–Aug) due September 15, 2026; Q4 (income Sep–Dec) due January 15, 2027. Note the unequal periods — Q2 covers only two months but is due June 16, not a typo. Most states follow similar schedules but may have different specific dates.

Estimate your total annual income from self-employment, subtract deductible business expenses to get net SE income, calculate SE tax (15.3% × 92.35% of net SE income), deduct half of SE tax and the standard deduction from AGI to get taxable income, apply federal brackets to get federal income tax, add state income tax if applicable, sum all taxes, and divide by 4 for your quarterly payment. This calculator performs all steps automatically.

The IRS charges an underpayment penalty if you owe $1,000 or more and your payments fall below the safe harbor thresholds. The penalty rate for 2026 is the federal short-term rate plus 3 percentage points (typically 7–8% annualized on the underpaid amount). This is charged per quarter, proportional to how long the underpayment existed. You avoid penalties by meeting safe harbor: paying 90% of the current year's tax, or 100% (110% if AGI > $150,000) of last year's tax liability.

To avoid the IRS underpayment penalty, you must pay the lesser of: (1) 90% of your current year's actual tax liability, or (2) 100% of your prior year's total tax liability (110% if your prior year AGI exceeded $150,000). Option 2 is often preferred because it lets you pay based on known information — last year's tax return — rather than estimating this year's income. If last year's return showed $16,000 in total tax, paying $4,000/quarter ($16,000 ÷ 4) guarantees no underpayment penalty regardless of how much you earn this year.

Divide your estimated annual tax liability by 12 to get a monthly set-aside amount. This calculator shows the exact monthly figure for your income and state. As a rough guide: set aside 25–30% of net income in no-tax states, or 30–40% in high-tax states. For simplicity, many self-employed workers transfer a fixed percentage of every payment received into a separate tax savings account immediately — before it gets spent.

It depends on the total amount. If your self-employment income is small and your W-2 withholding is sufficient to cover your total tax liability (meeting the safe harbor thresholds), you may not owe quarterly payments on your SE income. However, self-employment income from side work is often not covered by W-2 withholding. If you expect to owe more than $1,000 in total after withholding, quarterly payments are required. You can increase W-2 withholding via a new W-4 instead of making quarterly payments.

The easiest methods are IRS Direct Pay at IRS.gov/DirectPay (free, instant, no account needed) and EFTPS (Electronic Federal Tax Payment System) at EFTPS.gov (free but requires account setup a few days in advance). You can also mail a check with Form 1040-ES. For state quarterly payments, visit your state's Department of Revenue website — most states have online payment portals. Pay from a bank account rather than credit card to avoid processing fees.