See how the rules work.
Change one thing. Follow the effect. Five interactive studies connect tax calculations, partnership accounting, tax documents, and the taxpayer’s journey.
Follow a dollar through the 1040.
Income, adjustments, deductions, tax, and payments. Compare two scenarios and inspect every step.
Open the interactive guideOne transaction. Different ledgers.
See why a partner’s outside basis, partnership asset basis, and book capital tell different stories.
Open the interactive guideMake sense of an IRS notice.
Find the notice number, understand its place in the process, and return to the official guidance.
Open the interactive guideRead the document. Follow the field.
Decode 23 W-2 and partnership K-1 fields with fictional examples and links to the 2025 instructions.
Open the interactive guideA loss passes through separate gates.
Keep basis, at-risk, and passive-activity limits separate, with a distinct suspended bucket at each step.
Open the interactive guideFederal income tax
See how ordinary income moves through the federal brackets, using the basic standard deduction.
Explore the calculation Federal taxCapital gains stacking
Explore the 0%, 15% and 20% layers for eligible long-term gains and qualified dividends.
Explore the calculation Federal taxSelf-employment tax
Illustrate Social Security, Medicare and incremental Additional Medicare tax on one person’s business profit.
Explore the calculation