When you’re self-employed, no employer pays any part of your payroll taxes — you cover all of it yourself. This calculator helps you estimate how much that is: you enter your net profit and your own tax rate, and the calculator does the arithmetic. Nothing is hardcoded, so the result is always as current as the rate you enter.
How it works
The formula is straightforward:
Self-employment tax = Net profit × SE tax rate
That’s it. You bring the two numbers; the calculator multiplies them. The result is a rough estimate of what you’d owe in self-employment or payroll tax for the year.
Net profit is your business income after expenses — what you invoiced minus what you legitimately spent to earn it. SE tax rate is whatever combined payroll or self-employment rate applies where you are. You can look this up, use what a tax professional has told you, or use the default as a starting point and adjust.
Why you enter the rate yourself
Tax rates change. Governments update them, income thresholds shift, and what applies in one country is completely different in another. Instead of baking a rate into the calculator that would silently become wrong over time, we leave that field to you. If the rate changes next year, you just update the number you type in — the calculator itself never becomes outdated.
A worked example
Say your net self-employment profit is $80,000 and your combined SE tax rate is 15.3%.
SE tax = $80,000 × 15.3% = $12,240
That’s your estimated self-employment tax for the year. Adjust either number to test different scenarios — a different income, a different rate, or both.
What else affects your actual tax bill
This estimate covers one layer of tax — self-employment or payroll contributions. Your real total tax bill will also include income tax, which is a separate calculation. Use the freelance take-home calculator to see both layers together, or the quarterly tax calculator to break the annual total into four instalments.
Beyond those two layers, your actual bill may be affected by deductions, tax credits, income thresholds, regional rules and other factors that this calculator does not model. Treat the number here as a planning estimate, not a filing-ready figure, and confirm it with a licensed tax professional.