Self-employed workers need to plan for both income tax and self-employment tax. This guide shows what to estimate first so you can avoid underpayment surprises.
Maintained by the PayStubIQ Editorial Team · Updated July 14, 2026
See our editorial and calculation-review standards. No CPA or attorney review is claimed.
Start with expected annual net business income after ordinary business expenses, then estimate federal income tax, self-employment tax, and state tax separately. Keeping those lines separate makes it easier to see whether a change in income, expenses, or state assumptions is driving the result.
Most self-employed workers review quarterly estimates, but waiting until the deadline can make cash flow harder to manage. A practical workflow is to set aside tax money from each client payment, update the estimate monthly, and true up before each quarterly due date.
Many workers estimate only federal income tax and forget the self-employment tax that covers Social Security and Medicare. Model both, then compare the total against prior-year safe-harbor targets or professional guidance when income is changing quickly.
Worked example
Scenario: A consultant expects $96,000 of client payments and $18,000 of ordinary business expenses, leaving $78,000 of projected net profit. The consultant also has $20,000 of W-2 wages from part-time work.
Analysis: The planning base is the $78,000 profit, not the $96,000 deposited. W-2 wages matter because they may use part of the Social Security wage base and already provide some federal withholding. A useful forecast shows self-employment tax, federal income tax, state tax, and payments already made as separate lines.
Practical outcome: The monthly set-aside should be based on the remaining projected liability after W-2 withholding and estimated payments—not on a generic percentage of every deposit. Recalculate before each payment deadline using actual year-to-date profit.
No. It is an estimate and planning tool to help you set aside enough for taxes.
Many self-employed workers do, but requirements depend on your tax situation and prior-year payments.
These primary government sources support the rules or workflow discussed above. The note beside each link explains why it is relevant.
A common approach is a fixed savings percentage of each payment, then recalibrate quarterly based on actual income.
Yes, prior wage income can affect Social Security wage-base exposure.
Use these calculators to turn the guide into a more specific estimate for your pay, filing status, and state.