Sourdough · Engine TY 2025
Sourdough
Watch the math · Live engine demo

Type in what you made and what you drove. We show what you'll owe and the IRS rule behind every number.

This is the engine we'd use to file your taxes. Plug in your gig income, your business miles, and a few details about your phone and home office, and you'll see what you'd owe to the IRS and to California, broken down line by line. Every dollar on screen shows the rule behind it.

Inputs · Your line items
Gross receipts
$
Business miles
mi
Total miles (incl. personal)
mi
Phone (annual × business %)
$ × %
Home office (sqft, simplified)
sqft
Tax year
Ready.
Schedule C · Sole proprietor

Schedule C · Profit or Loss From Business

What you made from gigs, minus what you spent to do the job. What's left is what gets taxed.

Schedule SE · Self-employment tax

Schedule SE · 15.3% on 92.35% of net SE earnings

Social Security and Medicare on your gig income. As a W-2 employee your boss pays half; as a 1099 worker you pay both halves.

Form 1040 · Federal income tax

Form 1040 · Federal income tax

What you owe the federal government. We start from your business income, subtract a few standard deductions, and look up the tax in the IRS brackets.

Form 540 · California income tax

California Form 540 · State income tax

What California asks for. Mostly your federal number, with a few items California treats differently.

The bottom line
What you owe
Total tax $0.00
— %
Show the raw engine output (JSON) → 
…
This is exactly what we'd file for you. The citations come with.
Join the waitlist →
Not tax advice. This demo handles the simple case. A real return with multiple vehicles, Section 179 elections, depreciation, or QBI phaseouts will look more detailed than what you see here. The numbers shown are real.