How Much Should I Set Aside for Taxes on Side Hustle Income?

You picked up a side hustle, the money started coming in, and then the panic set in: nobody is withholding taxes from these payments. Unlike a regular paycheck, side hustle income arrives whole — and the government’s cut is still owed. If you spend it all, tax season becomes a bill you can’t pay.

The good news is the math is simpler than it feels, and once you know the percentage to hold back, the fear disappears. Here’s exactly how much to set aside, when it’s due, and how to track it so the number is never a surprise.

The Short Answer: Set Aside 25–30% of Net Profit

For most side hustlers, holding back 25% to 30% of your net income covers what you’ll owe. Net income means what’s left after business expenses — not your gross sales.

Why that range? Two taxes stack on side hustle income:

1. Self-employment tax: 15.3%. This is Social Security (12.4%) and Medicare (2.9%). At a regular job your employer pays half; on your own, you pay both halves.
2. Federal income tax: roughly 10–24% for most people, depending on your total household income and bracket.

Add a modest income-tax rate to the flat 15.3% self-employment tax and you land right around 25–30%. If you live in a state with income tax, or your side hustle pushes you into a higher bracket, aim for 30% or a little more to be safe. It’s far better to over-save and get a small refund to yourself than to come up short.

Set Aside on NET, Not Gross — This Is Where People Overpay or Underpay

The single most important word above is net. You owe tax on profit, not revenue. If you grossed $10,000 driving deliveries but spent $2,500 on gas, mileage, phone, and platform fees, your taxable profit is $7,500 — and you set aside a percentage of that $7,500, not the full $10,000.

This is why expense tracking isn’t optional busywork; it directly lowers your tax bill. Every deductible dollar you fail to record is a dollar you pay tax on unnecessarily. Common side hustle deductions include:

• Mileage (the IRS standard rate was 70 cents per mile in 2025 — that adds up fast for drivers)
• Platform and payment-processing fees
• Supplies, inventory, and shipping
• A portion of your phone and internet
• Software and subscriptions used for the hustle

Track these as you go and your “set aside 30%” is calculated on a much smaller, accurate number.

When It’s Due: Quarterly Estimated Taxes

Here’s the part that catches people off guard. The IRS doesn’t want all your side hustle tax in April — it wants it four times a year, as you earn it. If you expect to owe $1,000 or more for the year, you’re generally required to make quarterly estimated payments.

The 2026 estimated-tax due dates are:

• April 15, 2026 (for income earned Jan–Mar)
• June 15, 2026 (Apr–May)
• September 15, 2026 (Jun–Aug)
• January 15, 2027 (Sep–Dec)

Miss these and you can owe an underpayment penalty even if you pay your full balance at filing. This is exactly why setting money aside per payment matters — when the quarterly deadline arrives, the cash is already sitting in a separate account, waiting.

The System: A Separate Account + A Running Tracker

Two habits keep you out of trouble.

First, open a separate savings account for taxes. Every time income lands, move 30% of the net into it immediately. Treat that money as gone — because it is. It’s the IRS’s, you’re just holding it.

Second, keep a running tracker so you always know two numbers: your net profit so far this year, and your estimated tax owed to date. When you can see “$4,200 net profit, ~$1,260 tax reserve needed” at any moment, quarterly payments become a non-event.

Doing this by hand is tedious, which is why most side hustlers who stick with it use a spreadsheet that calculates the estimate automatically. The Side Hustle Income Tracker includes a self-employment tax estimator that applies the 15.3% SE tax and your income-tax rate to your live net profit, so your “set aside” number updates every time you log a payment.

What Happens If You Didn’t Save Enough?

If you’re reading this partway through the year and haven’t been setting money aside, don’t panic — act. Calculate your net profit so far, figure the tax on it, and start catching up on the next quarterly deadline. Increase your set-aside percentage temporarily to close the gap. The worst move is to ignore it and hope; the penalty and the shock only grow.

Make the Tax Number Boring

The reason side hustle taxes feel scary is uncertainty — not knowing the number until it’s too late to do anything about it. Set aside 25–30% of net profit, park it in a separate account, track your running total, and pay quarterly. Do that and tax season becomes a formality instead of a crisis.