US Estimated Tax
How much estimated tax do you owe this quarter?
For US freelancers and 1099 contractors. Enter your 2026 business income, or pull it from the invoices you marked paid, and see the self-employment tax, federal income tax, the safe-harbor amount that avoids the underpayment penalty, and what to pay by 15 January 2027.
- Runs
- In your browser
- Signup
- Not needed
- Licence
- MIT, open source
- Topic
- Money and paperwork
- 1.
Use it free
Open it in your browser. The first result needs no signup.
- 2.
Run it yourself
Open source under MIT. Take the code to your own server.
- 3.
Stay in touch
One email when it gets a new feature. Nothing else.
What it does
- Self-employment tax on 92.35 % of net profit: 12.4 % Social Security up to the 2026 wage base of $184,500 (minus your W-2 wages) and 2.9 % Medicare, plus the 0.9 % Additional Medicare Tax above $200,000.
- Federal income tax with the 2026 brackets and standard deduction ($16,100 single, $32,200 joint, $24,150 head of household), the deductible half of SE tax, itemized deductions and credits.
- The 20 % qualified business income deduction with the taxable income limit, the phase-out above $201,750 ($403,500 joint) and the new $400 minimum.
- Safe harbor: the smaller of 90 % of this year's tax or 100 % (110 % above $150,000 AGI) of last year's, the $1,000 rule, and the four installments with what is still open.
- Imports your income from HMSK Invoice: the invoices you marked paid in 2026, net of sales tax, read in your browser or from a backup file.
- Every 2026 figure is listed with its IRS or SSA source and an as-of date. Runs in your browser; inputs stay on your device or in a share link.
Why I built it
Quarterly estimated tax is the part of freelancing nobody explains well: four due dates, a penalty if you pay too little, and calculators that either want a signup or hide which rules they use. I wanted one that shows every number with its source, tells you the one amount to pay next, and takes the income straight from the invoices you already marked paid in my invoice tool, so the two work together.
Hafiz
Limits. An estimate, not tax advice. Federal tax only, no state tax. Figures as of 19 October 2026 (Rev. Proc. 2025-32, SSA). Check your numbers with a CPA, an enrolled agent or IRS Form 1040-ES.
Run it on your own server
Static files, no build step and no dependencies. Any web server works; tests run with Node.js 20+ (node --test tests/).
- Stack
- HTML, JavaScript
- Licence
- MIT
Also for your paperwork
Newsletter
Hear when US Estimated Tax gets better.
One email when US Estimated Tax or another tool gets a real update. A few times a year, no tracking.