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 If the rate changes next year, you just update the number you type in — the calculator itself never becomes outdated.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.
Self-employment tax versus income tax
These are two different obligations that often get conflated. Self-employment tax (or its equivalent in other countries) is the payroll-contribution layer — the Social Security and Medicare contributions in the US, National Insurance in the UK, or similar systems elsewhere. Income tax is a separate charge on your taxable income after applicable deductions.
As an employee, you only see one payroll contribution on your pay stub — the other half is paid by your employer and never appears in your take-home calculation. When you are self-employed, you cover both halves directly. This is why the self-employment tax rate in the US is 15.3% rather than 7.65%: you are paying what would otherwise be split between employee and employer. Some countries allow a partial deduction for the employer-equivalent portion, reducing the effective rate — but this calculator does not model that deduction, so if it applies to you, adjust the rate you enter downward accordingly.
Income tax is calculated separately and depends on your total taxable income, your filing status, applicable deductions and any credits. The combined burden — SE tax plus income tax — is what determines your actual cash obligation for the year. The quarterly tax calculator estimates both layers together.
How to use the result
The number this calculator returns is a planning estimate. Use it to:
- Set aside money from each payment you receive, so you have the funds when a quarterly or annual payment is due.
- Compare the tax burden across different revenue and expense scenarios.
- Understand roughly how much of your gross revenue is consumed by this one layer of tax.
Do not use this estimate to determine an amount to actually remit to a tax authority. Your real payment depends on your complete tax situation — deductions, credits, thresholds, other income sources, your choice of deductible expenses, and rules specific to your country and filing status. A licensed tax professional can determine that number accurately; this calculator cannot.
Why no rate is built in
Tax rates change. They vary by country, by year, by income level, and by legal structure. A self-employment tax rate that is correct today may be incorrect next year, and a rate that applies to a US sole proprietor is entirely different from what applies to a UK self-employed individual. Rather than maintain a database of rates that would need constant updates and would still be wrong for many users, this calculator leaves the rate field to you. Whatever rate you enter is the rate it uses — making the result as current and as accurate as your knowledge of your own situation.