Tax law, made
understandable.
Follow the reasoning behind the rules. Explore clear explanations, interactive calculators, and the original sources that bring U.S. tax law into focus.
the sourceCornell LIIINTERNAL REVENUE CODE ↗U.S. CodeOFFICIAL STATUTORY TEXT ↗eCFRTREASURY REGULATIONS ↗IRSGUIDANCE & INSTRUCTIONS ↗California FTBSTATE TAX RESOURCES ↗
Find your way into tax law.
Go straight to the authority
Move from a question to the Code, Treasury regulations, and clearly labeled agency guidance.
Learn by changing the numbers
Make the mechanics visible with 17 transparent tools for tax, partnership basis, and financial mathematics.
Make sense of Subchapter K
Connect contributions, allocations, basis, liabilities, and distributions in one research pathway.
A higher bracket.
A smaller mystery.
Moving into a higher bracket does not apply that rate to every dollar. Move the slider to see the layers.
2026 federal ordinary-income illustration · Single · Taxable income after deductions · Before credits and other taxes.
See the full calculationIncome is not cash.
Basis explains why.
A K-1 allocation and a distribution answer different questions. Follow a simple example from opening basis to closing balance.
Read the study noteIdeas worth understanding.
Three ledgers, three different questions
Outside basis, inside basis and book capital are related, but each follows a different ledger.
PartnershipsA guaranteed payment is not simply an owner draw
The payment formula and the partner’s role matter more than the label on the bank transfer.
Research methodFollow the rule back to its authority
A useful explanation is a starting point; the controlling text and applicable dates complete the research.
Follow the authority.
Sources sit beside explanations, so you can check the reasoning yourself.
Make assumptions visible.
Each tool states its scope. A useful illustration is not a complete tax return.
Keep learning open.
No paywall, sales funnel, or taxpayer-document uploads. Just a place to learn.