Quartli — Free Quarterly Tax Calculator for Freelancers (2026)
Quartli instantly calculates what self-employed workers owe the IRS each quarter. Enter your 1099 income and expenses; Quartli computes federal income tax (official 2026 brackets from IRS Rev. Proc. 2025-32), self-employment tax (15.3% on 92.35% of net earnings, $184,500 Social Security wage base), the Sec. 199A QBI deduction with Form 8995 limits, Additional Medicare Tax, NIIT, and safe-harbor payment amounts. Free, no signup required.
What Quartli calculates
- Federal income tax using official 2026 IRS brackets
- Self-employment tax with the Social Security wage base cap
- QBI deduction (Sec. 199A) with income phase-outs
- Additional Medicare Tax (0.9%) and Net Investment Income Tax (3.8%)
- Long-term capital gains and qualified dividend rates
- Safe harbor amounts to avoid underpayment penalties
2026 federal quarterly due dates
| Quarter | Income period | Federal due date |
|---|---|---|
| Q1 | Jan 1 – Mar 31, 2026 | April 15, 2026 |
| Q2 | Apr 1 – May 31, 2026 | June 15, 2026 |
| Q3 | Jun 1 – Aug 31, 2026 | September 15, 2026 |
| Q4 | Sep 1 – Dec 31, 2026 | January 15, 2027 |
Paid services
CPA-prepared state tax estimate: $29 one-time. CPA Review of your full tax picture with written Q&A: $99 one-time. Both performed personally by Lena Hanna, CPA, and delivered by email. See pricing.
Built by Lena Hanna, CPA. Free calculator at quartli.com/calculator. State-by-state guides at quartli.com/state-taxes.