Quarterly Estimated Tax Calculator (Form 1040-ES)

When You Must Pay Quarterly Estimated Tax

You're required to pay quarterly estimated tax (using Form 1040-ES) if you expect to owe $1,000+ in federal tax for the year after subtracting withholding and credits. This applies to: self-employed and 1099 contractors, gig workers (Uber, DoorDash, Instacart), landlords with positive rental income, investors with significant capital gains or dividends, and anyone with side income not subject to withholding. Source: IRS Publication 505, IRS.gov. Last updated: May 2026.

Safe-Harbor Rules — The 100% / 110% / 90% Tests

The IRS gives you THREE ways to avoid underpayment penalty — pay the smallest amount that satisfies any one:

• 100% of last year's tax (if your AGI was $150,000 or less)
• 110% of last year's tax (if AGI was over $150,000)
• 90% of this year's actual tax liability

Most contractors use the prior-year rule because it's predictable — pay last year's tax amount, regardless of how this year ends up. Even if you actually owe $30,000 this year, paying $16,500 (last year's number) protects you from penalty.

2026 Quarterly Tax Deadlines

If the date falls on a weekend or holiday, the deadline moves to the next business day. Late payments trigger penalty calculated from the original due date.

How to Pay — Three Easy Methods

(1) IRS Direct Pay (irs.gov/payments) — free bank-account transfer, no signup, immediate confirmation. Best for most filers. (2) EFTPS (eftps.gov) — Electronic Federal Tax Payment System. Requires one-time enrollment. Better for business owners with payroll and recurring schedule. (3) Mail Form 1040-ES with check — slowest method but works. Always use certified mail. Avoid debit/credit card payment processors that charge 1.9-2.4% fee.