Wisconsin · WI
Wisconsin Quarterly Estimated Tax Calculator (2026)
Calculate the quarterly federal + Wisconsin state tax payments required to stay penalty-safe with the IRS and Wisconsin Department of Revenue.
Wisconsin LLC owners and self-employed individuals must make quarterly estimated tax payments to both the IRS and the Wisconsin Department of Revenue. Missing a federal quarterly payment triggers an IRS underpayment penalty calculated at the short-term rate + 3% (currently ~8% annualized). Wisconsin also assesses underpayment interest at Wisconsin-specific rates. The calculator below estimates your per-quarter federal + state combined payment.
See the full Wisconsin LLC tax calculator for annual modeling, or the S-Corp election guide if you're considering reducing SE tax via Form 2553.
Quarterly Estimated Tax Calculator (2026)
Self-employed LLC owners owe federal and state taxes four times a year, not just at filing. Skip a payment and the IRS underpayment penalty is currently ~8% annualized. This calculator estimates how much to send each quarter to stay penalty-safe.
Total annual tax estimated: $28,503. Safe-harbor (90% of current year) per quarter ≈ $6,413.
2026 IRS quarterly due dates
| Period | Due | Amount |
|---|---|---|
| Q1 (Jan 1 – Mar 31) | April 15, 2026 | $7,126 |
| Q2 (Apr 1 – May 31) | June 15, 2026 | $7,126 |
| Q3 (Jun 1 – Aug 31) | September 15, 2026 | $7,126 |
| Q4 (Sep 1 – Dec 31) | January 15, 2027 | $7,126 |
How to actually pay
- Federal: IRS Direct Pay (irs.gov/payments) or EFTPS — free, instant.
- State: Most state Department of Revenue portals (each state's own e-file system).
- Form 1040-ES: The federal estimated tax voucher; required only if mailing a check.
- Safe harbor: Pay either 90% of current-year tax or 100%/110% of last year's tax — whichever is smaller — to avoid penalty.