Safe Harbor Estimated Tax Calculator

Federal  •  All 50 States  •  Quarterly Payment Schedule
IRC §6654IRS Pub. 505Federal + All 50 States + DC2025 - 2026
← cpavalidated.com
IRC Sec. 6654 Federal + All 50 States 2025 / 2026
1

Tax Information

Safe harbor amounts are based on prior year tax liability (100% rule) or current year estimated tax (90% rule). The 110% rule applies federally when prior year AGI exceeds $150,000 ($75,000 MFS). State rules vary - see the state table below for jurisdiction-specific rules and thresholds.
2

Federal Safe Harbor Analysis

Federal Inputs
Prior year federal tax liability$0
Prior year AGI$0
110% rule applies (AGI > $150,000)?No
90% of current year estimated tax$0
100% / 110% of prior year tax$0
Safe Harbor Amount (90% Rule)
$0
90% of current year estimated tax - IRC Sec. 6654(d)(1)(B)(i)
Safe Harbor Amount (Prior Year Rule)
$0
100% of prior year tax - IRC Sec. 6654(d)(1)(B)(ii)
Use This Safe Harbor Amount
$0
Lower of the two amounts (pay this to avoid underpayment penalty)
Per Quarter Payment
$0
Annual safe harbor / 4 equal installments
110% Rule: If your prior year federal AGI exceeded $150,000 ($75,000 if MFS), the prior year safe harbor increases from 100% to 110% of prior year tax. This is the most commonly missed federal estimated tax rule. - IRC Sec. 6654(d)(1)(B)(ii).

Federal Quarterly Payment Schedule

Federal estimated tax payments are due April 15, June 15, September 15, and January 15 of the following year. If the due date falls on a weekend or holiday, it shifts to the next business day. Payments are made via IRS Direct Pay, EFTPS, or with Form 1040-ES. - IRC Sec. 6654(c).
3

All 50 States - Safe Harbor Reference

State Income Tax Safe Harbor Rule Annual Safe Harbor Per Quarter Q1 Due Q2 Due Q3 Due Q4 Due Notes
State safe harbor amounts are estimated based on the prior year state tax entered above, adjusted by the applicable state percentage. Actual state amounts may vary based on state-specific AGI thresholds, filing status adjustments, and other factors. Verify with your state's department of revenue before filing. "Special" due dates differ from the standard federal schedule.
This tool is for informational purposes only and does not constitute tax advice. Tax determinations are fact-specific. Consult a qualified tax professional before making any filing or planning decisions. A tk.cpa resource - tk.cpa.
tk.cpa AI Lab
Mission Privacy tk.cpa
Nothing on this page constitutes legal, tax, accounting, or professional advice, and no professional relationship is created by your use of this website. CPA Validated is an educational website for information purposes only. Information should be verified against current primary authority, including the Internal Revenue Code, Treasury regulations, IRS guidance, and applicable state or local law, before being relied upon or acted on. Calculator outputs are estimates only and may be incomplete or inaccurate depending on the facts, assumptions, and inputs used. CPA Inc. and tk.cpa disclaim liability to the fullest extent permitted by law. Full disclaimer: cpavalidated.com/disclaimer.html