Self-employed people pay both halves of Social Security and Medicare, a combined 15.3%, plus regular income tax. This calculator estimates the whole bill and what to set aside each quarter.
How self-employment tax works
- SE tax applies to 92.35% of net profit.
- Social Security is 12.4% on that amount up to $184,500 in 2026.
- Medicare is 2.9% on all of it, plus 0.9% above the high-income threshold.
- You deduct half of your SE tax when computing income tax.
- Many sole proprietors can also deduct 20% of qualified business income.
Quarterly estimated tax due dates for 2026
| Period | Due date |
|---|---|
| Jan 1 to Mar 31 | April 15, 2026 |
| Apr 1 to May 31 | June 15, 2026 |
| Jun 1 to Aug 31 | September 15, 2026 |
| Sep 1 to Dec 31 | January 15, 2027 |
This is an estimate for planning. It does not include state tax, other income, or credits, and the 20% business deduction is limited at higher incomes.