Freelancer Quarterly Estimated Tax Calculator

• Calculates self-employment tax (Social Security and Medicare on net self-employment earnings) and federal income tax together.
• Automatically applies the Qualified Business Income (QBI) deduction and the self-employment tax income deduction, the same way a real return would.
• Accounts for wages from a regular job affecting the Social Security wage base.
• Subtracts tax already withheld to show what's actually still owed in estimated payments.

How to use this calculator

Enter the projected annual net profit from self-employment — revenue minus deductible business expenses, not gross revenue — along with filing status. If there's also income from a regular job, enter those wages under Advanced, along with any federal tax already withheld and an approximate state/local tax rate if wanted.

How the estimate works

Self-employment tax and federal income tax are calculated together, since self-employment tax affects the income tax calculation through two deductions:

Self-employment tax = 15.3% (Social Security + Medicare) on 92.35% of net profit
Income tax deduction = half of self-employment tax, deducted above the line
QBI deduction         = generally 20% of qualified business income, subject to limits

The total of self-employment tax plus federal income tax, minus anything already withheld, is divided by four for the quarterly payment amount.

A worked example

$80,000 in net self-employment profit, filing single with no other income, produces a combined self-employment and federal income tax bill that — divided across four quarterly payments — typically comes out in the low thousands per quarter, after the QBI deduction and the self-employment tax adjustment are both applied.

The safe harbor rule

The IRS generally waives underpayment penalties if total withholding and estimated payments equal at least 90% of the current year's tax, or 100% of last year's tax (110% if last year's adjusted gross income was above $150,000) — whichever is smaller. For freelance income that varies a lot from year to year, basing quarterly payments on last year's actual tax bill is often simpler and safer against penalties than trying to project the current year precisely.

Assumptions and limitations

• Federal tax only, precisely. State and local income tax is only a flat-percentage estimate, not a real state tax calculation.
• Doesn't model tax credits such as the child tax credit or health insurance premium tax credit, both of which are common for self-employed filers and can reduce what's actually owed.
• Assumes a steady net profit projection. Real freelance income often varies month to month — revisiting the estimate partway through the year as actual income becomes clearer is worth doing.

Common mistakes

Using gross revenue instead of net profit. Self-employment tax and income tax are both based on profit after business expenses, not total revenue — using the wrong figure significantly overstates the tax owed.

Forgetting to pay quarterly at all. Unlike a W-2 job where an employer withholds tax automatically, self-employment income has no automatic withholding — skipping quarterly payments can lead to a large bill and a penalty at filing time, even if the total tax paid for the year eventually catches up.

Not adjusting the estimate when income changes mid-year. A strong quarter or a slow one can change what the remaining quarterly payments should be — the safe harbor rule provides a floor, but overpaying or underpaying the actual liability by a wide margin isn't ideal either way.

Frequently asked questions