Gig Worker Tax Toolkit

Tax toolkit for 1099 gig workers and freelancers: 2026 quarterly estimates, self-employment tax, safe harbor check, and the mileage deduction with the July 2026 rate change (72.5 to 76 cents) handled correctly.

Know what to set aside, and when to pay it

For DoorDash, Uber, Lyft, Instacart, freelance and any 1099 income. Deterministic federal math using the official 2026 figures.

Tools

• estimate_quarterly_tax: self-employment tax (92.35% of net, Social Security to the $184,500 base, Medicare, additional Medicare), federal income tax with 2026 brackets and standard deduction, the 20% QBI deduction when eligible, what is still owed, and an even split across the remaining real due dates (Apr 15, Jun 15, Sep 15, Jan 15).
• calculate_mileage_deduction: priced per trip by date. The IRS changed the 2026 business rate mid-year: 72.5 cents through June 30, then 76 cents from July 1. Most calculators apply one rate to the whole year.
• check_safe_harbor: the minimum you must pay to avoid an underpayment penalty (90% of this year or 100%/110% of last year).
• compare_mileage_vs_actual: standard mileage against actual vehicle expenses, with the rules that lock the choice in.
• get_tax_constants: every figure used and its source.

Limits

Federal only (optional flat state rate). Single and married filing jointly. Excludes credits, itemized deductions and retirement contributions, and does not apply the QBI deduction above the phase-out. An estimate for planning, not tax advice.

Use it

Hosted on MCPize with a free tier (10 calls a day). Remote MCP endpoint (streamable HTTP, API key from MCPize):

https://gig-tax-mcp.mcpize.run/mcp

Or run it yourself:

npm install
node server.js   # listens on :8080, MCP at /mcp

MIT licensed.