Assumptions & data sources
Displayed at county resolution. Sales & local-income taxes (ZIP-level underneath) are population-weighted to a county rate; property tax is county-level; state income tax is state-level. Within-county variation is averaged out.
Income type. "Wages" incurs Social Security + Medicare payroll tax; "Retirement / investment" does not (but income tax still applies, and retirement-income exclusions and preferential capital-gains rates are not modeled). Married-jointly uses a single Social Security wage base, so a two-earner couple's payroll tax is slightly understated. No itemized deductions, tax credits (e.g. EITC — overstates very low incomes), or exemption phase-outs; NY's tax-benefit recapture (understates high NY earners) and federal-tax deductibility in LA/MO (overstates those) are also not modeled. Alabama's federal-tax deduction and AGI-phased standard deduction, and Arkansas's published bracket schedule and low-income table, are modeled.
Local income tax is modeled in MD, IN, OH, PA, KY, MI, NY, IA, plus Kansas City/St. Louis, Wilmington, and major Alabama cities. Not modeled: Oregon's Portland-metro/Multnomah taxes (they apply only above ~$125k) and minor municipal occupational taxes. MD, IN, MI and NYC are levied on a net figure (their deductions/exemptions come off first); OH/PA/KY are levied on gross, as they are in law. Approximations: NYC is a flat 3.5% (actually graduated); Iowa surtaxes use a county average; OH/PA/KY use each ZIP's dominant municipality (small enclaves inherit the larger city's rate); the county value is a population-weighted blend, so a partly-taxed county shows a partial rate.
Sales tax applies to the taxable share of spending you set (default 65%); rent and many services/groceries are exempt in reality. Combined rates use the lowest rate within each 5-digit ZIP where a ZIP spans jurisdictions.
Property tax = county median effective rate × the house price you enter (the rate is taxes paid over home value, so assessment ratios are already baked in, but caps and homestead exemptions are not — a new buyer in a capped state such as California under Prop 13 would pay more than shown). Connecticut's rates are its 2023 planning-region values mapped onto the legacy counties. Because the Census caps its reported county medians, effective rates are slightly understated in a few very-high-value counties and floored in a few near-zero-tax rural areas. A few counties with suppressed Census data show as no-data (gray).
Color scale spans the smallest to largest non-zero value of the selected layer for your current inputs, and re-scales whenever you change an input — so shading is relative to the current scenario, not an absolute dollar scale, and two scenarios aren't directly color-comparable. On the dollar layers, counties where the selected tax is $0 (e.g. no state income tax or no sales tax) are white and sit outside the scale; on the ÷ income layer, 0% stays on the scale. Gray means no data.
Sources: Census ACS 5-yr 2023 (property), Streamlined Sales Tax + state DORs (sales), state DORs (income), municipal/county registers (local income). Rates reflect 2025 law; a few source files are effective into 2026 (e.g. some sales-tax tables). Not tax advice — a directional estimate.