How the 1099 Tax Calculator Works

1. Net SE Income = Gross Income - Business Expenses

2. SE Tax = (Net SE Income x 0.9235) x 15.3%

3. SE Deduction = SE Tax / 2 (deducted from AGI)

4. QBI Deduction = Net SE Income x 20% (simplified)

5. Taxable Income = AGI - Standard Deduction - QBI

6. Federal Income Tax = applied via 2026 brackets

7. Quarterly Payment = (SE Tax + Federal Tax + State Tax) / 4