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Pennsylvania · Quarterly Payments · Safe Harbor · 2026 IRS Data

Quarterly Tax Calculator 2026 — Pennsylvania

Self-employed workers in Pennsylvania must make quarterly estimated payments to both the IRS and the Pennsylvania tax authority — missing either can result in underpayment penalties. This calculator shows your combined quarterly estimated tax obligations in Pennsylvania and how much to set aside each month.

Also see: Pennsylvania Self-Employed Tax Calculator →

Expected Income This Year

$

Your expected gross revenue for 2026

$

Deductible expenses reduce your taxable income

Your 2026 Quarterly Payments

Q1 (Jan–Mar)

$4,065

Due April 15, 2026

Q2 (Apr–May)

$4,065

Due June 16, 2026

Q3 (Jun–Aug)

$4,065

Due September 15, 2026

Q4 (Sep–Dec)

$4,065

Due January 15, 2027

Total estimated tax$16,258
Effective rate on $75,00021.7%
Set aside per month$1,355

How It's Calculated

Gross income$75,000
Business expenses−$10,000
Net SE income$65,000
SE tax (15.3% × 92.35%)−$9,184
Federal income tax−$5,078
State tax−$1,996
Total annual tax$16,258
Per quarter (÷ 4)$4,065

Safe Harbor Rule

To avoid IRS underpayment penalties, pay at least 90% of this year's tax OR 100% of last year's tax liability (110% if last year's AGI exceeded $150,000), whichever is smaller.

90% of this year's tax

$3,658/qtr

Enter 2025 liability above for prior-year safe harbor

How to Pay Quarterly Taxes

Pay online at IRS.gov/DirectPay or via EFTPS (Electronic Federal Tax Payment System). Most states accept payment through their official tax portals. Mail payments with Form 1040-ES.

Frequently Asked Questions

Does my state have quarterly estimated tax payments too?

Most states with an income tax require quarterly estimated payments on self-employment income, similar to federal requirements. Thresholds and due dates vary by state — some states use the same due dates as federal, others differ slightly. Generally, if you owe more than $500–$1,000 in state tax for the year, you'll need to make quarterly state payments as well. Check your state's Department of Revenue website for exact thresholds and due dates.

What is the underpayment penalty rate for 2026?

The IRS underpayment penalty rate for 2026 is the federal short-term rate plus 3 percentage points — typically 7–8% annualized on the underpaid amount. The penalty is calculated quarterly and applied proportionally to how long the underpayment existed. To avoid it entirely, meet the safe harbor: pay 90% of this year's tax or 100% (110% if AGI > $150,000) of last year's total tax liability, in equal quarterly installments.