Graduated rates aren't the complicated part of the tax system. The complicated part is figuring out the amount the rate applies to. E.g. capital gains, deductio

Graduated rates aren't the complicated part of the tax system. The complicated part is figuring out the amount the rate applies to. E.g. capital gains, deductions, credits. If you have never filed your own tax return before, go skim the instructions for form 1040[0] (117 pages). It includes a 10 page table for the graduated tax rate so most people don't need to do any arithmetic if they make <100,000. Besides a couple tables like that and some administrative pages, the rest is text and worksheets for figuring the amount to apply the rate to. And this is just the basic form that everyone files! There are additional forms someone might file for complex circumstances, let alone filings for all the kinds of trusts and corporations. 0: https://www.irs.gov/pub/irs-prior/i1040gi--2018.pdf https://www.irs.gov/pub/irs-prior/i1040gi--2018.pdf