This is a planning estimate, not tax advice. It doesn't calculate your actual income tax, credits, deductions, state tax or the additional 0.9% Medicare tax. For your real numbers, use IRS Form 1040-ES or a tax professional.
Self-employment tax
Self-employment tax is Social Security and Medicare for people who work for themselves. Following IRS Schedule SE:
- Net earnings from self-employment = net profit × 92.35%.
- Social Security: 12.4% of net earnings, up to that year's wage base. The Social Security Administration sets the base at $184,500 for 2026 and $192,300 for 2027. W-2 wages count toward the base first.
- Medicare: 2.9% of all net earnings.
SE tax generally applies if net earnings from self-employment are $400 or more.
Income tax at your rate
Income tax depends on your filing status, deductions, credits and other income, so the estimator doesn't try to calculate it. Instead it applies the rate you enter to net profit minus half of SE tax (you can deduct half of SE tax when calculating income tax). Many freelancers use last year's return to pick a planning rate.
Safe harbor
You generally avoid the federal underpayment penalty if your withholding and timely estimated payments are at least the smaller of 90% of this year's tax or 100% of last year's tax (110% if last year's AGI was over $150,000, or $75,000 if married filing separately). Enter last year's total tax to see the quarterly payment that meets the prior-year test.
Due dates
For tax year 2026 the payments are due April 15, June 15 and September 15, 2026, and January 15, 2027. For tax year 2027 they are due April 15, June 15 and September 15, 2027, and January 18, 2028. The IRS can move dates, for example for disaster relief, so confirm on the current Form 1040-ES. Our quarterly estimated taxes guide explains each step.
Frequently asked questions
Why are the quarters different lengths?
The IRS periods are January to March, April to May, June to August and September to December, so the second payment covers only two months.
What percentage should I set aside?
The estimator shows your total estimate as a percent of profit. Moving that percent from every client payment into a separate account is a simple way to be ready each quarter.
Is my income information sent anywhere?
No. The estimator runs in your browser. Nothing is saved, sent or logged.
Read the full guide
Sources
Results are estimates for planning, not professional advice. Check the official sources above for rules that apply to you.