1099 Tax Estimator

Enter your expected primary W-2 salary, your estimated 1099 side-gig revenue (locums, moonlighting, consulting), and your estimated deductible business expenses.

The estimator calculates the resulting net business profit and estimates exactly how much of that extra income you need to set aside for quarterly estimated tax payments.

When you earn W-2 income, your employer automatically withholds Federal, State, and payroll taxes from every paycheck. When you earn 1099 independent contractor income, zero taxes are withheld.

Physicians who moonlight are often surprised in April by massive tax bills and IRS underpayment penalties because they didn't realize they were responsible for remitting estimated taxes on that side income 4 times a year.

Net Business Income: 1099 Revenue - Deductible Business Expenses.

Total Tax Liability: Because the W-2 income fills up the lower tax brackets, every dollar of 1099 net income sits on "top" of it and is taxed at your highest marginal bracket (often 32% to 37% Federal). Additionally, 1099 income is subject to Self-Employment (SE) tax (Medicare).

• Pearl: Maximize your 1099 deductions. You can deduct mileage driven to moonlighting shifts, CME costs, scrubs, stethoscopes, and board exam fees, directly reducing the taxable net profit of the side gig.
• Pitfall: Forgetting about State taxes. This calculator estimates Federal and SE taxes. If you live in a high-tax state like California or New York, you need to withhold an additional 5% to 10% for state quarterly payments.
• Pearl: If you have 1099 income, you can open a Solo 401(k). This allows you to shelter roughly 20% of your net business profit from taxes, completely separate from your W-2 hospital's 401(k) / 403(b) limits.