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US Freelancer Tax Calculator 2026

Official registry Finance and payments

2026 US freelancer tax: quarterly estimates, SE tax, mileage, home office, SEP/401(k), per diem.

Source code Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package freelance-tax-mcp
Claude Code 
claude mcp add us-freelancer-tax-calculator-2026 -- npx -y freelance-tax-mcp@1.2.0
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "us-freelancer-tax-calculator-2026": {
            "command": "npx",
            "args": [
                "-y",
                "freelance-tax-mcp@1.2.0"
            ]
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. freelance-tax-mcp
  2. Tools
  3. Install
  4. Example
  5. Prefer a web page?
  6. License

freelance-tax-mcp

A free Model Context Protocol (MCP) server for US freelancer and sole-proprietor taxes in 2026: quarterly estimated tax with the safe harbor, self-employment tax, IRS due dates, the IRS mileage deduction (including the July 1, 2026 rate change) the home office deduction, and the most you can put into a SEP IRA vs a Solo 401(k). Everything runs locally: no API key, no account, no network calls.

Tools

ToolWhat it does
estimate2026 federal estimate from net_profit (or ytd_profit + months): SE tax, income tax, QBI, safe-harbor quarterly payment and due dates. Options filing_status, w2_wages, withholding, prior_year_tax, prior_year_agi, state_rate_pct.
self_employment_taxSocial Security and Medicare tax on net profit, the deductible half and Additional Medicare Tax.
due_datesQuarterly estimated tax due dates for a year, moved past weekends and DC legal holidays.
mileageStandard mileage deduction priced by the date of each trip (business 72.5 cents Jan to Jun 2026, 76 cents from Jul 1), from a trip log or split totals.
mileage_ratesIRS mileage rates by period with sources.
home_officeSimplified ($5 per sq ft, up to 300 sq ft) vs regular Form 8829 method, with the income limit and carryovers.
retirement_contribution2026 SEP IRA vs Solo 401(k) maximum contribution for a sole proprietor or single-member LLC (IRS Pub. 560 rate worksheet): employer share, $24,500 deferral, catch-up ($8,000 at 50+, $11,250 at 60 to 63), the $72,000 cap, which plan allows more and estimated income tax saved. Options age_group, w2_wages, other_deferrals, plan_rate, bracket.
tax_figures2026 brackets, standard deductions, SE tax figures and official IRS/SSA sources.

Figures come from IRS Rev. Proc. 2025-32, the SSA 2026 wage base ($184,500), Form 1040-ES (2026), IRS Announcement 2026-11, Pub. 587, Pub. 560 and IRS Notice 2025-67 (2026 retirement plan limits). Planning estimates only; not tax, legal or accounting advice.

Install

Requires Node.js 18 or newer.

npx -y freelance-tax-mcp

Add to your MCP client's config (for Cursor, ~/.cursor/mcp.json):

{
  "mcpServers": {
    "freelance-tax": { "command": "npx", "args": ["-y", "freelance-tax-mcp"] }
  }
}

From source: git clone https://github.com/NarwhalThePong/freelance-tax-mcp.git && cd freelance-tax-mcp && npm install && npm test.

Example

estimate with { "net_profit": 80000 } (single, no other income) returns self-employment tax of $11,303.64, total 2026 federal tax of $16,647.47 and a quarterly payment of $4,161.87, with the four due dates.

retirement_contribution with { "net_profit": 100000 } (under 50) returns a SEP IRA maximum of $18,587.04 and a Solo 401(k) maximum of $43,087.04 ($24,500 deferral + $18,587.04 employer share).

Prefer a web page?

Disclosure: these are our own free pages.

License

MIT

Frequently asked questions

What is US Freelancer Tax Calculator 2026?

2026 US freelancer tax: quarterly estimates, SE tax, mileage, home office, SEP/401(k), per diem.

How do I install US Freelancer Tax Calculator 2026?

It runs on your machine. In Claude Code: claude mcp add us-freelancer-tax-calculator-2026 -- npx -y freelance-tax-mcp@1.2.0. For other clients, paste the JSON configuration from this page into their MCP settings.

Does US Freelancer Tax Calculator 2026 need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is US Freelancer Tax Calculator 2026 open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains US Freelancer Tax Calculator 2026?

It is published by NarwhalThePong. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.