Methodology

What tax this is

Greenville County Council adopted the enacting ordinance on July 21, 2026 (8–3), placing a 1% transportation sales tax on the November 3, 2026 ballot under S.C. Code § 4-37-30 (Title 4, Ch. 37, “Optional Methods for Financing Transportation Facilities”). The rate piggybacks on the state sales tax base defined in Title 12, Chapter 36, with specific carve-outs.

The tax collects for a maximum of eight years from the date of imposition, which the ordinance sets at May 1, 2027 (§2.2, §2.5). It can end sooner: collection stops if the tax raises the $1,100,000,000 the ballot names (§2.6). Continuing it past that point would require a new public vote.

How the county splits the money

Question 1 prints a ceiling for each county purpose: no more than $990,000,000 for roads, bridges, other transportation-related projects and related drainage; $33,000,000 for mass transit; and $77,000,000 for greenbelts. Together they equal the ballot’s $1,100,000,000 cap. The comparison table uses those figures directly: the ordinance caps mass transit at 3% and greenbelts at 7% of the tax collected, and the $990,000,000 roads ceiling is 90% of the total. They are ceilings, not guaranteed spending shares or floors.

Source: Greenville County Ordinance No. 1324, §2.4(i)–(iii), as adopted on third reading July 21, 2026.

What is taxed and what is exempt

Exempt by state statute

• Motor fuel (gasoline, diesel): § 12-36-2120(15)
• Prescription drugs: § 12-36-2120(28)
• Residential electricity, natural gas, and fuel oil: § 12-36-2120(33)
• Water sold by public utilities: § 12-36-2120(12)
• Home internet access: exempt under the federal Internet Tax Freedom Act (P.L. 114-125, made permanent in 2016). State and local governments are preempted from taxing internet access charges. Note: this applies only to the broadband access line itself, not to streaming subscriptions or cable TV, which are taxed.
• Maximum-tax items, including vehicles, motorcycles, boats, aircraft, recreational vehicles, and manufactured homes, are excluded from this local transportation tax under § 4-37-30(A)(9). Their state tax treatment varies: § 12-36-2110 sets a $500 maximum for the listed vehicle and similar items, while manufactured homes have a separate calculation and a $300 maximum when they meet specified energy-efficiency standards. Vehicles subject to SCDMV’s infrastructure maintenance fee are exempt from sales tax (§ 56-3-627; § 12-36-2120(83)).

Exempt under the adopted ordinance (§2.9)

Unprepared groceries. At the July 21, 2026 final reading, Council adopted the ordinance's §2.9 amendment, electing the broad unprepared-food exemption under § 4-37-30(A)(9): unprepared food items eligible for USDA food coupons, exempt for all buyers, not only SNAP recipients. Motor fuel, prescription drugs, medicine, and prosthetic devices are also confirmed exempt under the adopted ordinance. The calculator treats groceries as exempt throughout, matching the adopted text.

Taxed

Everything else that is subject to the state sales tax: prepared food (restaurants, takeout), clothing, furniture, appliances, electronics, alcoholic beverages, tobacco products, telecommunications services, pet supplies, personal care products, books, magazines, and general retail. Event admissions are not on this list: tickets to movies, concerts, games, and attractions pay the state’s separate 5% admissions license tax (§ 12-21-2420), not the sales tax this measure piggybacks on.

Spending data

Each slider is one category of monthly spending. Its default is a starting estimate selected for the income preset, not a measurement of a typical Greenville household. Adjust the sliders to reflect your own spending; the tax estimate updates as you do.

The starting estimates draw on two kinds of information:

• BLS Consumer Expenditure Survey, Table 1203 (2024, published December 2025) supplies national spending categories and income-bracket comparisons. The model groups and adjusts those categories for taxable household spending. 2024 income table (Excel)
• Industry research provides context for phone and streaming costs. These surveys and customer samples cover different populations from BLS, so the selected defaults are modeling choices rather than a single survey’s results.

Selected defaults and assumptions

• Cell phone, cable & streaming: the $77k preset starts at $225/month for mobile service and streaming, without assuming cable. For context, Deloitte’s 2026 survey reports average streaming spending of $69/month among subscribing households. Mobile bills vary by plan and number of lines; adjust the combined slider for your services.
• Dining out: the $350/month default at the $77k preset is a selected starting amount for restaurants, takeout, and similar spending. Use the slider to reflect your household’s actual monthly spending.
• Entertainment & hobbies: the 55% taxable share is an assumption for a category mixing taxable goods with untaxed services. Admissions are excluded: ordinary event tickets pay the separate admissions license tax (§ 12-21-2420), rather than the Chapter 36 sales tax. See the taxable-fraction table below.

The presets use the national BLS income brackets below as reference points. The $77k preset is anchored at $76,932, Greenville County’s median household income in the Census ACS 2020–2024 5-year estimate (table B19013). The selected spending values are stored in the model’s data file.

BLS surveys consumer units, which are not exactly the same as households. The 5-year Census estimate provides the local income anchor; the BLS spending information is national.

Income brackets used

The $200k+ button represents the BLS open-ended top bracket, whose mean income is $322,142 because it includes all households above $200k. We label it "$200k+" rather than "$300k" to match the source data.

Interpolation between brackets

For custom incomes between presets, the calculator interpolates the logarithms of both income and each category’s spending amount. This log-log interpolation is a modeling choice that connects the selected defaults; it is not a fitted local spending curve. The result is rounded to the slider’s step size. Exact presets retain their selected values, and incomes outside the preset range use the nearest endpoint.

Taxable fractions per category

Some BLS categories mix taxable and non-taxable things together, so treating one as fully taxed would overstate what a household pays. The table below gives the taxable fractions used by the calculator. The three fractions below 100% are assumed category mixes, not percentages set by tax law or measured for every household:

The fixed “Other taxed retail” line is a selected allowance for housekeeping supplies, OTC medical supplies, reading material, and other small taxable purchases. It varies with income but is not adjustable with the sliders. At the $77k preset it adds $57/month of spending, or about $7/year of tax, even if every slider is set to zero.

The exempt utilities line

The spending breakdown shows a household's combined monthly cost for water, electricity, and natural gas alongside the taxed categories. This line adds nothing to the tax estimate. It shows how much of the monthly budget the tax does not reach. Residential electricity and natural gas are exempt under § 12-36-2120(33); water sold by public utilities is exempt under § 12-36-2120(12).

The starting amounts draw on BLS CEX 2024 Table 1203: the annual means for Electricity, Natural gas, and Water and other public services, summed and divided by twelve, with a curated value at the local-median preset ($238/mo at $42k, $273 at $77k, $326 at $150k, $385 at $200k+). The BLS "Water and other public services" line also includes trash collection and septic service, so the displayed lump slightly overstates pure water spending.

What Charleston’s collections can tell us

The SCDOR compliance audit dated December 11, 2025 reports Charleston County transportation-tax collections of $767,078,714 from July 1, 2019 through June 30, 2024. Two half-percent taxes ran concurrently during that period, for a combined 1%. The five-year total averages about $153 million annually.

Those receipts include purchases by visitors and businesses as well as resident households. Dividing them by a household count would not isolate what residents paid. An assumed resident share would produce an illustrative scenario, not a measured household cost or an upper limit.

Charleston’s receipts therefore provide context for tax collections, but do not validate this calculator’s household estimate. The estimate here comes from the spending amounts and taxable-share assumptions described above.

The combined outlook for city voters

For a household in a city with its own 1% question, the combined outlook assumes both the county and city measures pass. It varies the city-taxable share of the modeled spending from 0% to 100%, giving an outer range for those inputs. It is not a guarantee of actual cost: spending, taxable category mixes, and credits can differ from the assumptions.

The four cities are within Greenville County, and both taxes use the Chapter 36 base with the exemptions described above. The model treats the entered taxable spending as subject to the county tax. City tax ranges from zero to the same amount. Tax location includes applicable purchases delivered or used in the city, not just shopping at a physical store. Mobile service, for example, is generally sourced to the customer’s place of primary use under §§ 12-36-1920 and 12-36-1930. A household with those services may not be able to reach the zero-city-tax endpoint simply by shopping elsewhere.

The city credit starts with the city’s published projection for a first full collection year, generally tax year 2028, rather than the smaller partial-year credit. The source and year appear with the estimate. The credit is recalculated annually, so future amounts may change.

combined = [ county − usable credit , (2 × county) − usable credit ]

Under Act 228, signed May 19, 2026, the credit applies to qualifying owner-occupied property assessed at 4% and cannot exceed existing municipal ad valorem tax liability (§ 5-41-120(C)(3)). Its gross amount uses the property’s capped tax value before the homestead exemption (§ 5-41-170(A)). Renters and owners of nonprimary residences receive no credit in this estimate.

The calculator asks whether you receive the § 12-37-250 homestead exemption. For qualifying owners, it removes the first $50,000 of value from the modeled municipal tax liability. If you choose “Not sure,” the result covers both exemption possibilities until you confirm. A qualifying homestead property valued at $50,000 or less has no modeled municipal liability to offset.

The liability limit is also an estimate. It uses the entered capped property value, the 4% assessment ratio, and 2025 municipal operating millage. That historical rate may differ from the rate in the projected credit year. Other exemptions and adjustments are not modeled. The usable credit cannot exceed your actual municipal ad valorem liability; county taxes, school taxes, and fees cannot increase that limit.

The break-even amount divides estimated usable credit by the 1% city rate. It is the annual city-taxable spending that would offset that credit; it does not offset the county tax. If homestead status is uncertain, the calculator shows the corresponding range.

break-even city spending = usable credit ÷ 0.01

What this calculator does not model

• Spending variation within a bracket. Two households at the same income can pay very different amounts depending on whether they dine out, smoke, drink, own pets, or travel. The defaults are starting estimates; adjust them for your circumstances.
• Major one-time purchases. A household buying a new couch, a new laptop, or furnishing a first apartment will pay more in that year than the starting estimate.
• Tourism and business spending. Some share of the total tax collected by the county will come from visitors and businesses, not residents. This calculator estimates one household’s spending-related cost, not its share of all county collections.
• Regional price differences. BLS national data does not capture Greenville-specific price levels or shopping patterns.

Limitations and caveats

• The grocery exemption is adopted ordinance text (§2.9, adopted at the July 21, 2026 final reading); the model matches it.
• The $200k+ bracket is open-ended and averages in ultra-high-income households. The $200k+ button uses the selected $322,142 income anchor. Custom incomes above that anchor retain its defaults; use the spending sliders to reflect your household.
• Custom incomes below $42,000 or above the top bracket use the nearest preset’s defaults rather than extrapolating further.
• The $42k/$77k/$150k custom-income interpolation is anchored at the preset incomes ($42,000 / $76,932 / $150,000), not at the BLS bracket means shown in the table above (e.g., $83,888 for the $77k tile). A household entering its literal $83,888 income is interpolated partway toward the $150k tile rather than centered on its own bracket's average. The preset anchors are a modeling choice.
• Treat this as an estimate built on selected spending amounts and tax assumptions. Tracking your taxable purchases can help you choose more representative inputs.
• Source data is the 2024 calendar year, released by BLS in December 2025. The municipal credit projections and liability assumptions also need review as newer city figures become available.

Sources

Statutes and official guidance

• S.C. Code § 4-37-30: Title 4, Ch. 37, "Optional Methods for Financing Transportation Facilities"
• S.C. Code Title 12, Chapter 36: sales and use tax base and exemptions
• Act 228 of 2026, Municipal Tax Relief Act: enacted municipal tax and credit rules
• S.C. Code § 12-37-250: homestead exemption
• SC DOR Sales & Use Tax Manual: official DOR guidance on exemptions
• Internet Tax Freedom Act: federal preemption on taxing internet access

Spending data

• BLS Consumer Expenditure Survey tables (Table 1203, 2024)
• J.D. Power TV & Internet Bills Q1 2025
• Reviews.org State of Consumer Media Spending 2025
• Astound Average Cell Phone Bill 2026
• Deloitte Digital Media Trends 2026
• AAA, Your Driving Costs 2025 (vehicle maintenance average)

Income and city credit data

• US Census: Greenville County, SC
• City of Greenville: Municipal Tax Relief Act
• City of Mauldin: Municipal Tax Relief Act (FY2027–28 credit table)
• Simpsonville June 2026 staff memo (FY2027–28 credit table); current city program page
• Travelers Rest: tax relief and published credit multiplier

The sources above inform the model. Selected spending amounts and taxable fractions remain estimates, and city credits depend on future collections and property values.

Last updated: September 8, 2026.