Free, accurate calculators for 2026. Compare LLC vs S-Corp, estimate self-employment tax, and plan quarterly payments — no sign-up required.
Compare total tax burden and find your breakeven point for electing S-Corp status.
Calculate 15.3% SE tax, federal income tax, QBI deduction, and effective rate.
Find your IRS safe harbor amount, payment schedule, and underpayment penalty risk.
Every calculator includes an in-depth guide with step-by-step explanations, 2026 tax parameters, and common mistakes to avoid.
| Parameter | Value |
|---|---|
| Social Security wage base | $184,500 |
| Standard deduction (single / MFJ / HoH) | $16,100 / $32,200 / $24,150 |
| Top marginal rate | 37% (over $640,600 single) |
| QBI deduction | 20% of qualified business income |
| Additional Medicare threshold | $200K single / $250K MFJ |
| Quarterly due dates | Apr 15, Jun 15, Sep 15, Jan 15 |
Sources: IRS Rev. Proc. 2025-45, IRS Publication 15, IRS Publication 505. All calculators use these official 2026 parameters.