Whether you drive a gas-powered sedan, a diesel pickup, a hybrid, a plug-in, or a fully electric vehicle, the cost of getting from A to B is more complicated than the sticker price on a gallon of fuel. Maryland’s 2026 fuel economy calculator breaks that cost into precise, verifiable pieces — and this guide explains every one of them in plain English.
Why Maryland Needs Its Own Calculator
Fuel costs vary significantly from state to state because of excise taxes, electricity rates, and registration surcharges. Maryland is no exception. As of July 1, 2025, the state charges $0.4600 per gallon in excise tax on gasoline and $0.4675 per gallon on diesel — figures set by the Maryland Comptroller and adjusted annually for inflation. Crucially, Maryland’s 6% sales tax does not apply at the pump; only the excise tax does.
Meanwhile, average retail gasoline in Maryland sat at approximately $4.01 per gallon in March 2026 (AAA Maryland), diesel at around $5.78 per gallon (AAA), and residential electricity at 20.61 cents per kWh according to the U.S. Energy Information Administration’s January 2026 data. A calculator that uses national averages would give Maryland drivers the wrong numbers.
The Inputs: What You Tell the Calculator
Before any math happens, you choose your vehicle type — gasoline, diesel, hybrid (HEV), plug-in hybrid (PHEV), or battery electric (BEV). That single choice determines which fields appear and which formulas apply. Other key inputs are:
| Input | Default Value | Typical Range |
|---|---|---|
| Annual miles driven | 12,000 mi | 0 – 100,000 |
| City driving percentage | 55% | 0% – 100% |
| Gasoline price | $4.00 / gal | $0.50 – $10.00 |
| Diesel price | $5.00 / gal | $0.50 – $10.00 |
| Electricity price | $0.2061 / kWh | $0.05 – $0.40 |
| Maintenance cost | $0.11 / mile | $0 – $0.50 |
Annual mileage default based on Maryland survey data (~12,900 mi/yr estimated); 12,000 used as conservative default. City/highway split follows EPA label weighting. Maintenance figure from AAA’s 2025 Your Driving Costs study (11.04¢/mi average).
1 Combining City and Highway MPG
Most vehicles have separate city and highway MPG ratings. The calculator combines them using the harmonic mean — not a simple average. This matters because MPG is a rate (miles per gallon), and averaging rates incorrectly inflates the result.
The formula: divide 1 by the sum of (city fraction ÷ city MPG) plus (highway fraction ÷ highway MPG). The city fraction defaults to 55% and highway to 45%, matching the EPA’s official label weighting for combined ratings.
Example 1 — Compact Gas Car
City MPG: 30 | Highway MPG: 40 | City driving: 55%
Harmonic mean = 1 ÷ (0.55 ÷ 30 + 0.45 ÷ 40)
Combined MPG = 33.8 MPG
Example 2 — PHEV on Gas Mode
City MPG: 42 | Highway MPG: 38 | City driving: 55%
Harmonic mean = 1 ÷ (0.55 ÷ 42 + 0.45 ÷ 38)
Combined MPG = 40.1 MPG
2 The Real-World Adjustment
EPA test numbers are measured under controlled laboratory conditions. Real-world driving — with traffic lights, air conditioning, cold starts, and varying speeds — typically lowers efficiency by about 10%. The calculator applies a 0.9 multiplier to MPG for gas vehicles, and a ÷ 0.9 adjustment (meaning 11% more energy consumed) for electric vehicles.
Example 1 — Gas Car After Adjustment
EPA Combined MPG: 33.8
33.8 × 0.9
Real-world MPG = 30.4 MPG
Example 2 — BEV After Adjustment
EPA rating: 30 kWh per 100 miles → 0.30 kWh per mile
0.30 ÷ 0.9
Real-world consumption = 0.333 kWh per mile
3 Fuel Cost Per Mile
This is the core calculation, and it differs by vehicle type. For all gas and diesel vehicles, the total cost per gallon (retail price plus excise tax) is divided by the real-world MPG. For electric vehicles, the electricity price is multiplied by kWh consumed per mile. PHEVs blend both calculations based on the percentage of miles driven on electricity.
For Gasoline Vehicles
Example 1 — Compact Gas Car
Gas price: $4.00 + MD excise tax: $0.46 = $4.46 per gallon
$4.46 ÷ 30.4 MPG (real-world)
Fuel cost = 14.7¢ per mile
Example 2 — Diesel Truck
Diesel price: $5.00 + MD diesel tax: $0.4675 = $5.47 per gallon
Real-world MPG: 28.8 | $5.47 ÷ 28.8
Fuel cost = 19.0¢ per mile
For Battery Electric Vehicles
Example 1 — Compact BEV
Electricity price: $0.2061/kWh | Consumption: 0.333 kWh/mi
$0.2061 × 0.333
Fuel cost = 6.9¢ per mile
Example 2 — Larger BEV (40 kWh/100 mi)
Real-world: 0.40 ÷ 0.9 = 0.444 kWh/mi | $0.2061 × 0.444
Fuel cost = 9.2¢ per mile
For Plug-in Hybrids (PHEV)
PHEVs split their driving between a gasoline engine and an electric motor. You enter the percentage of your miles driven on electricity. The calculator computes each cost separately, then blends them by those percentages.
Example 1 — PHEV at 50% Electric
Gas cost/mi: $4.46 ÷ 36.1 MPG = 12.4¢ | Electric cost/mi: $0.2061 × 0.333 = 6.9¢
Blended: (50% × 12.4¢) + (50% × 6.9¢)
Fuel cost = 9.6¢ per mile
Example 2 — PHEV at 75% Electric
Gas cost/mi: 12.4¢ | Electric cost/mi: 6.9¢
Blended: (25% × 12.4¢) + (75% × 6.9¢)
Fuel cost = 8.3¢ per mile
4 CO₂ Emissions Per Mile
The calculator uses EPA combustion factors for tailpipe emissions: 8,887 grams of CO₂ per gallon of gasoline and 10,180 grams per gallon of diesel. Electric vehicles produce zero tailpipe emissions, but their grid-sourced electricity does carry upstream CO₂. Maryland draws power from the PJM grid, estimated at approximately 300 grams CO₂ per kWh (EPA/EEI 2020 data, used as the 2026 default).
Example 1 — Gas Car CO₂
8,887 g/gal ÷ 30.4 MPG
Tailpipe CO₂ = 292 grams per mile (3.5 metric tons/year at 12,000 mi)
Example 2 — BEV Grid CO₂
300 g/kWh × 0.333 kWh/mi
Upstream CO₂ = 100 grams per mile (1.2 metric tons/year) — zero tailpipe
5 Energy Metrics and MPGe
To compare vehicles across fuel types on equal footing, the calculator converts everything into a common energy unit. The EPA established that 33.7 kWh of electricity contains the same energy as one gallon of gasoline. This gives us MPGe — miles per gallon equivalent — which puts a 100-MPGe electric vehicle and a 33-MPG gas car on the same scale.
Example 1 — BEV MPGe
Consumption: 0.333 kWh per mile
33.7 ÷ 0.333
MPGe = 101 MPGe
Example 2 — PHEV Blended MPGe
Blended energy: 2,234 BTU per mile (50/50 gas-electric split)
120,214 BTU/gal ÷ 2,234 BTU/mi
MPGe = 53.8 MPGe
6 Maryland’s EV and PHEV Surcharge
Because electric and plug-in vehicles pay little or no fuel tax (which funds road maintenance), Maryland introduced annual ZEV registration surcharges beginning in January 2025. These are set by the Maryland Department of Transportation: $125 per year for battery EVs and $100 per year for PHEVs. The calculator spreads this annual fee across your miles to express it as a per-mile cost.
Example 1 — BEV Surcharge at 12,000 mi/yr
$125 ÷ 12,000 miles
Surcharge = 1.04¢ per mile
Example 2 — PHEV Surcharge at 8,000 mi/yr
$100 ÷ 8,000 miles
Surcharge = 1.25¢ per mile
7 Total Annual Operating Cost
The full annual cost adds four items together: annual fuel cost, annual maintenance cost, the vehicle registration fee, and the EV/PHEV surcharge (if applicable). The registration fee for a typical passenger car under 3,500 lbs in Maryland is $120.50 per year, which includes the $40 Emergency Medical Services surcharge, per the Maryland Motor Vehicle Administration. Heavier vehicles pay $125.50 or $191.50 per year.
| Vehicle | Fuel/yr | Maintenance/yr | Registration | EV Surcharge | Total/yr |
|---|---|---|---|---|---|
| Compact Gas | $1,759 | $1,320 | $120.50 | — | $3,199 |
| Midsize Hybrid | $1,155 | $1,320 | $120.50 | — | $2,596 |
| PHEV (50% elec) | $1,154 | $1,320 | $120.50 | $100 | $2,694 |
| Compact BEV | $824 | $1,320 | $120.50 | $125 | $2,390 |
Maintenance rate of $0.11/mi from AAA’s 2025 Your Driving Costs study. Registration fees from Maryland MVA fee schedule.
8 The Optional Titling Tax
If you’re buying a vehicle, Maryland charges a 6.5% titling tax on the purchase price (or fair market value), with a minimum of $41.60. This is a one-time cost, separate from annual operating expenses, and the calculator displays it on its own rather than folding it into cost-per-mile.
Example 1 — Mid-Range Sedan at $35,000
$35,000 × 6.5%
Titling tax = $2,275
Example 2 — Used Car at $8,000
$8,000 × 6.5%
Titling tax = $520 (well above the $41.60 minimum)
What the Calculator Does Not Include
No tool captures everything. The calculator is transparent about its assumptions and gaps. Insurance is not modeled (AAA’s full cost of ownership including insurance runs $0.77–$1.00/mi, but insurance varies too much by driver profile). Idling and congestion losses are approximated by the 0.9 real-world adjustment rather than modeled separately. Tiered electricity pricing (summer vs. winter rates, time-of-use plans) is not modeled — a flat average rate is used instead. Vehicle manufacturing emissions are excluded; only fuel-cycle CO₂ is counted. Finally, all prices and tax rates reflect 2026 figures and should be updated annually as Maryland’s CPI-linked excise taxes adjust each July 1.
The Bottom Line
At 12,000 miles per year and current Maryland prices, a compact gas car costs roughly 25.7¢ per mile all-in, a hybrid drops that to around 21–22¢, and a battery EV comes in near 18.9¢ — before accounting for any federal EV tax credits or utility rebates. The EV’s advantage is almost entirely in fuel savings; its maintenance cost is assumed to be the same as a gas car in this model (a conservative assumption, since EVs generally need fewer oil changes and brake jobs).
CO₂ tells a similar story: the gas car emits roughly 3.5 metric tons of tailpipe CO₂ per year, while the same mileage in a BEV produces 1.2 metric tons of upstream grid emissions — and zero at the tailpipe. As Maryland’s grid continues to incorporate more renewable energy, that EV number will fall further over time.
The formulas in this calculator are not estimates or rules of thumb. They are the same methods used by the EPA, DOE, and AAA to calculate official fuel economy and ownership cost figures — applied specifically to Maryland’s 2026 tax rates, utility prices, and fee schedules.
Sources and References
All data is from official government, utility, and industry sources. Monetary figures reflect 2026 values and should be reviewed annually.
- Maryland Comptroller — Motor Fuel Tax Rates: Gasoline excise tax $0.4600/gal, diesel $0.4675/gal (effective July 1, 2025). marylandtaxes.gov
- AAA Maryland — Fuel Gauge Report (March 2026): Average regular gasoline ~$4.01/gal; diesel ~$5.78/gal. gasprices.aaa.com
- U.S. Energy Information Administration (EIA) — State Electricity Profiles, January 2026: Maryland residential rate 20.61¢/kWh; commercial rate 18.19¢/kWh. eia.gov
- Maryland Motor Vehicle Administration (MVA) — Registration Fee Schedule: Passenger car under 3,500 lbs: $120.50/yr; 3,500–3,700 lbs: $125.50/yr; over 3,700 lbs: $191.50/yr (includes $40 EMS surcharge). mva.maryland.gov
- Maryland Code, Transportation Article — EV Surcharges: BEV annual surcharge $125/yr; PHEV annual surcharge $100/yr (effective January 2025). MD Code Trans. §13-955.
- Maryland Code, Transportation Article — Titling Tax: 6.5% of vehicle purchase price or fair market value, minimum $41.60. MD Code Trans. §13-809.
- U.S. Department of Energy (DOE) / EIA — Fuel Properties: Gasoline 120,214 BTU/gal (35.2 kWh); diesel 137,381 BTU/gal (40.2 kWh); 1 kWh = 3,412 BTU. afdc.energy.gov
- EPA — MPGe Definition: 33.7 kWh = 1 gallon gasoline (energy equivalence basis for electric vehicle ratings). fueleconomy.gov
- EPA — CO₂ Emission Factors: Gasoline 8,887 gCO₂/gal; diesel 10,180 gCO₂/gal (combustion-only, tailpipe). epa.gov/greenvehicles
- EPA / Edison Electric Institute (EEI) — Maryland Grid Emissions: PJM grid approximately 300 gCO₂/kWh (2020 data; used as 2026 default). epa.gov/egrid
- EPA — City/Highway Drive Cycle Weighting: Combined MPG label uses 55% city / 45% highway harmonic weighting. fueleconomy.gov
- AAA — Your Driving Costs Study (2025): Average maintenance and repair cost 11.04¢/mile; total cost of ownership $0.77–$1.00/mile including insurance and depreciation. newsroom.aaa.com
- Maryland Department of Transportation (MDOT) / ZEEVIC — EV Registrations (2024): Approximately 121,000 BEV and PHEV registrations in Maryland, representing ~2.3% of all registered vehicles.
- EIA — National Diesel Prices (March 2026): National average approximately $4.92/gal. eia.gov