Free Tax Calculators

See what to pay the IRS each quarter for 2026, with an optional California estimate and safe harbor check.

Compare a sole proprietorship or LLC with an S-Corp: payroll taxes, QBI, California taxes, retirement limits and added costs.

Compare the simplified and regular methods for renters and owners, and see the estimated tax saved.

Estimate late filing and late payment penalties, plus interest, on an unpaid federal tax balance.

Compare the 2026 standard mileage rate with actual vehicle expenses and see the estimated tax saved.

Estimate a reasonable owner salary from BLS wage data, adjusted for your role, experience, license and hours.

Check each state's economic nexus threshold, see which sales count, and estimate tax at current state rates.

Enter an IRS, FTB or EDD notice number to see what it means in plain language, the deadline and next steps.