After-Tax Side Income Calculator
Side income is not all yours. Some of it belongs to taxes you have not paid yet. This calculator gives a rough after-tax estimate so you stop spending money you may owe.
Last updated June 2, 2026
It is a planning tool, not a tax return. The percentages are assumptions you control. For exact filing decisions, talk to a tax professional.
When to use this calculator
- You already know gross side profit and want a rough after-tax monthly figure.
- You are deciding how much of side cash is safe to spend or send to debt.
- You mix W-2 and self-employment and need a separate reserve on side profit.
Inputs you need
- Monthly gross side income and business expenses.
- Federal, state, and self-employment reserve percentages you choose for planning.
Expenses people forget
- Expenses that reduce taxable profit (not every personal bill qualifies).
- Quarterly payments you should fund from the reserve, not lifestyle.
Your numbers
Example values are shown so you can see how it works. Replace them with your own.
- Taxable profit$900
- Total reserve rate31.3%
- Estimated tax reserve- $282
- After-tax monthly$618
- After-tax yearly$7,420
- Effective bite of gross28.2%
Move the reserve into a separate account as you earn so the tax bill does not come out of money you have already spent.
Estimates only, based on the numbers you enter. Nothing is saved to the page address. Tax figures are rough planning numbers, not filing advice.
Assumptions this calculator makes
- Tax reserve, state, and self-employment percentages are assumptions you set, not official rates.
- Self-employment tax is applied to taxable profit in this rough model.
- Real tax depends on total household income, deductions, and filing status.
- This is a planning estimate, not tax advice. Consult a tax professional for filing.
This is an estimate, not advice
Every result here is a rough model based only on the numbers you enter. Sidequity is an informational tool and does not provide professional, tax, legal, investment, or financial advice, and it makes no income guarantees. Any tax set-aside is a planning placeholder, not a tax calculation.
How to interpret the result
After-tax monthly is the realistic amount this income adds to your life once taxes are respected.
If the effective bite is large, the income is still useful, but plan around the smaller number.
What this calculator does not know
- Deduction eligibility, credits, or spouse income effects.
- Exact IRS or state brackets for your household.
- Whether you should make estimated payments (ask a tax professional).
Common mistakes
- Spending side income before setting aside the tax portion.
- Forgetting self-employment tax, which can be the biggest piece for gig and freelance work.
- Ignoring deductible expenses that would lower taxable profit.
- Assuming a refund will cover it instead of reserving as you go.
Suggested next steps
- Move the reserve to a separate account when payouts land.
- Pair with side hustle income calculator if you have not modeled hours yet.
- Read side hustle taxes basics for orientation, not filing advice.
Estimates only. Not tax, legal, or financial advice.
Frequently asked questions
Does this file my taxes?
No. It is a rough planning estimate so you can set money aside. Your real liability depends on your full situation, and you should confirm it with a tax professional.
What is self-employment tax?
It covers Social Security and Medicare for self-employed people and is often around 15.3 percent of net profit. Many new side hustlers forget it, which is why it has its own field here.
What reserve percentage should I use?
Many people start around 25 to 30 percent of profit combined, but the right number depends on your income and location. Use a tax professional to set yours.
Do expenses really lower my taxes?
Legitimate business expenses reduce taxable profit, which lowers the amount taxed. Keep clear records and confirm what qualifies with a professional.
After-Tax Side Income Calculator last updated June 2, 2026. Back to all calculators.