1099 quarterly tax calculator (2026)
Estimate self-employment tax and the extra federal income tax on your freelance or side-hustle profit, and what to pay each quarter.
Estimated tax on your business for 2026
| Net profit | |
| Self-employment tax | |
| Social Security (12.4%) | |
| Medicare (2.9%) | |
| Extra federal income tax | |
| State set-aside | |
| Each quarterly payment | |
| Share of profit to set aside |
Get the tracker (£9 / about $12)
2026 estimated-tax due dates
- Q1 (Jan 1 – Mar 31): April 15, 2026
- Q2 (Apr 1 – May 31): June 15, 2026
- Q3 (Jun 1 – Aug 31): September 15, 2026
- Q4 (Sep 1 – Dec 31): January 15, 2027
How it's calculated
Self-employment tax is 15.3% of 92.35% of your net profit: 12.4% Social Security (only on the first $184,500 of combined wages and self-employment earnings in 2026) and 2.9% Medicare. No SE tax is due if net earnings are under $400. Half of it is deductible. Federal income tax uses the 2026 brackets and standard deduction ($16,100 single, $32,200 married filing jointly). We show only the extra tax your business adds on top of any W-2 wages.
Worked example: $40,000 income minus $6,000 expenses is $34,000 profit. SE tax: $34,000 × 92.35% × 15.3% = $4,804.05. Taxable income: $34,000 − $2,402.02 (half of SE tax) − $16,100 = $15,497.98. Federal tax: $1,240 + 12% × $3,097.98 = $1,611.76. Total about $6,415.80, or $1,603.95 a quarter (19% of profit).
What's left out?
The Qualified Business Income (QBI) deduction (which can lower your tax), credits, the 0.9% Additional Medicare Tax, AMT, retirement and health-insurance deductions, and your state's rules. The estimate errs on the high side.
How do I avoid an underpayment penalty?
Generally, by paying on time at least 90% of this year's tax or 100% of last year's (110% if your AGI was over $150,000). See IRS Form 1040-ES.
Sources: IRS self-employment tax, 2026 Form 1040-ES, IRS IR-2025-102 (2026 brackets). Estimate only; not tax advice.