Side Hustle / 1099 Quarterly Tax Estimator

Side hustle income doesn’t have taxes withheld the way a W-2 paycheck does — you owe both self-employment tax (Social Security and Medicare) and income tax on it, and the IRS expects you to pay estimated tax quarterly if you’ll owe $1,000 or more for the year. This calculator estimates both pieces using current 2026 tax rules, and shows the incremental tax caused specifically by your side hustle profit — not your total tax bill — so you know how much to actually set aside from what you’re earning on the side.

Net Side Hustle Profit This Year ($) — revenue minus expenses Other W-2 Income ($) — leave 0 if side hustle is your only income Filing Status Estimated State Tax Rate on Profit (%)

Why Side Hustle Income Gets Taxed Twice

As a W-2 employee, your employer pays half of your Social Security and Medicare taxes automatically. As a self-employed side hustler, you’re both the employer and the employee, so you owe the full 15.3% self-employment tax (12.4% Social Security up to the annual wage base, plus 2.9% Medicare with no cap) on top of ordinary income tax on the same profit. The IRS does let you deduct half of that self-employment tax when calculating your income tax, which this calculator applies automatically.

Why This Shows the “Incremental” Tax, Not Your Total Tax

If you also have a W-2 job, your employer already withholds tax on that income. What catches side hustlers off guard is the additional tax created specifically by stacking side hustle profit on top of that income at your marginal rate. This calculator computes your income tax with and without the side hustle profit and shows only the difference — that difference, plus the full self-employment tax, is what you actually need to set aside and pay quarterly that your day job isn’t already covering.

A Few Practical Notes

Quarterly estimated payments are typically due in mid-April, June, September, and January for the prior quarter’s income — check IRS.gov for exact dates, which shift slightly year to year. This calculator assumes your side hustle profit is already net of business expenses (supplies, mileage, home office, etc.); tracking those deductions accurately can meaningfully lower what you owe. It also doesn’t account for the Qualified Business Income (QBI) deduction, which many self-employed filers can claim and which would reduce the income tax portion shown here. Consult a tax professional for your exact quarterly payment obligation.

Freedom Wealth Lab Apps provides general educational tools, not personalized tax advice. Read our full Disclaimer and Affiliate Disclosure. Data source: IRS self-employment tax rules and 2026 federal tax brackets.