Quarterly Tax Set-Aside Calculator
Estimate how much side hustle profit to save for quarterly taxes. Includes self-employment tax, federal brackets, state tax, and a safety buffer.
How to Use This Calculator
- 1.Enter monthly net profit after ordinary business expenses
- 2.Add W-2 income so federal brackets are not understated
- 3.Include state tax, prior payments, and a safety buffer
- 4.Save the scenario and update it as income changes
Why Quarterly Tax Planning Matters
Side hustle income usually arrives before taxes are withheld. That makes gross profit feel spendable even when a meaningful part belongs in a tax bucket.
The safer habit is to move a percentage of net profit as soon as the money lands. A weekly or monthly transfer rule is easier to follow than rebuilding a year of income right before a deadline.
Use this estimate with the broader cashflow tools if your income varies month to month or you run more than one income stream.
Common Questions
How much should I set aside for quarterly taxes?
Many side hustlers start with 25-35% of net profit, but the right number depends on your W-2 income, filing status, state taxes, deductions, and how much you have already paid. This calculator estimates a more specific set-aside using self-employment tax plus incremental federal and state tax.
Does this include self-employment tax?
Yes. The calculator uses the IRS self-employment tax method: 15.3% applied to 92.35% of net self-employment profit, then accounts for the deductible half of self-employment tax when estimating federal income tax.
Why does W-2 income matter?
Side income stacks on top of your other income for federal income tax. A person with higher W-2 income may owe a higher marginal tax rate on the same side hustle profit than someone with lower total income.
Are quarterly tax dates always the same?
Federal estimated tax due dates usually fall in April, June, September, and January, but holidays and weekends can move deadlines. Always confirm current IRS and state deadlines before paying.
Is this tax advice?
No. This is a planning estimate for side hustle cashflow. It does not replace tax software, IRS guidance, state tax rules, or advice from a qualified tax professional.
Methodology & Limits
How it works
This calculator calculates a universal tools scenario from your inputs, then surfaces the result as decision-oriented numbers.
Assumptions
Uses current tax rates assumptions where relevant.
Use it as a screen
Treat the output as a planning estimate. Save or share scenarios; saved versions stay local to your browser. Validate the numbers with real payouts, costs, deadlines, and local rules before committing money.
Next action
Keep Going
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