Cost Per 100 Miles Calculator
Dollars per gallon and cents per kilowatt-hour cannot be compared by eye, which is why the gas versus electric argument so often goes in circles. Cost per 100 miles ends the argument: it converts both fuels into the same unit, the money it takes to cover a fixed distance, and lets the cheaper option identify itself.
Use fuel mode to compare a gas car and an EV side by side from efficiency and energy prices, with the annual difference at your yearly mileage. Use trip mode after a real drive, entering what it cost and how far you went, to get the per-100-miles figure for that journey.
Fuel and energy cost only. Real-world efficiency varies with speed, weather, and driving style, and public fast charging commonly costs two to three times home electricity rates.
Quick Answer
Key takeaways
- Per-100-miles is the common currency: gas divides price by MPG, electric multiplies consumption by the kWh rate, and both land in dollars for the same distance.
- Home charging is where the EV advantage lives. At public fast-charging prices of $0.40 a kWh, the same EV costs $12.00 per 100 miles and the gas car pulls level.
- Annualize before you decide. A $7.00 gap per 100 miles sounds small until it becomes $840 a year at average mileage.
- Trip mode audits reality. Feed it a finished journey and it tells you what your driving, your weather, and your charging mix actually cost.
How to use the cost per 100 miles calculator
Leave the mode on Gas vs EV comparison for the standard question. Enter the gas car’s real MPG and the price you pay per gallon, then the EV’s consumption in kWh per 100 miles and your electricity price, and set your annual mileage so the tool can scale the gap to a year. The consumption figure is printed on every EV’s EPA listing as kWh/100 mi, and most EVs also report it in the trip computer; fueleconomy.gov publishes the official figure for every model year if yours is not to hand.
Switch to trip mode when the question is about a drive that already happened: a road trip, a month of commuting, a delivery route. Enter the total energy cost and the miles, and the calculator returns the cost per 100 miles and per mile for that journey. Run your regular commute through trip mode once and you own a number most drivers only guess at, which pairs well with the commute expense calculator when you cost the whole door-to-door trip.
Two formulas, one scale
Each vehicle needs one formula, and both produce dollars per 100 miles.
The gas formula works because 100 / MPG is simply the gallons a 100-mile drive burns: 100 / 30 is 3.33 gallons, and 3.33 gallons at $3.45 is $11.50. The EV formula is even more direct, because consumption is already stated per 100 miles: 30 kWh at $0.15 is $4.50. Divide either result by 100 for the per-mile figure. Nothing in the comparison depends on battery size, tank size, or range; those decide how often you stop, not what the miles cost.
Worked example: the same 12,000 miles, two fuel bills
The calculator is pre-filled with this comparison, and every figure below is what it returns.
| Measure | Gas car | EV (home charging) |
|---|---|---|
| Efficiency input | 30 MPG | 30 kWh/100 mi |
| Energy price | $3.45/gal | $0.15/kWh |
| Cost per 100 miles | $11.50 | $4.50 |
| Cost per mile | $0.12 | $0.05 |
| Annual fuel at 12,000 miles | $1,380 | $540 |
The third bar is the one comparison articles leave out. The EV in this example is not inherently cheap per mile; it is cheap at home electricity prices. Charge it mostly at a $0.40 per kWh fast charger and it costs $12.00 per 100 miles, a touch more than the gas car it was beating by $840 a year. Your charging mix is the single biggest variable in the whole comparison.
The charging reality check
US residential electricity averaged roughly 18 cents per kWh in mid-2026 according to Energy Information Administration data, with state averages running from under 13 cents to over 40. Home charging at those rates keeps an efficient EV in the $4 to $6 per 100 miles band. Time-of-use plans sharpen the edge: overnight off-peak rates near $0.10 per kWh pull the worked example down toward $3.00 per 100 miles, and scheduling the charge is usually a setting in the car, not a chore.
Public DC fast charging plays by different economics. Networks price for speed and location, commonly $0.30 to $0.50 per kWh, and at those rates the EV advantage shrinks to a rounding error against an efficient gas car or hybrid. Road-trip-heavy drivers should run this calculator twice, once at their home rate for daily miles and once at a fast-charge rate for trip miles, and weight the two by how they actually drive. Drivers costing the full picture rather than the fuel slice should add the fixed side too: the car insurance cost per month calculator covers the premium that dwarfs fuel for many households, and the battery cost calculator prices the long-life component EV shoppers worry about most. For the shortest trips, the honest benchmark is not another car at all: the bike cost per ride calculator shows how close to zero a two-mile journey can get.
What competing calculators miss
Most tools in this space answer a bigger question than the one being asked, and lose the answer inside it.
Miss 1: ownership models bury the fuel figure. Total cost of ownership calculators fold in purchase price, depreciation, incentives, and finance charges, then present one giant number. The fuel comparison, the part that changes with every price swing, becomes unrecoverable. This page isolates it: four inputs, the per-100-miles answer, the annual difference.
Miss 2: no trip mode. Comparison tools work from ratings and assumptions. Trip mode works from your receipt and your odometer, which is the only version of the number that reflects your speed, your hills, and your winter.
Miss 3: one electricity price, presented as universal. Tools that hardcode a national average kWh rate miss that EV running cost is really a charging-mix question. Here the rate is yours to set, and the article shows what happens to the answer across the home-to-fast-charge range.
Frequently Asked Questions
Divide 100 by your MPG, then multiply by the price per gallon: (100 / MPG) x price per gallon. At 30 MPG and $3.45 a gallon that is 3.33 gallons x $3.45, which is $11.50 per 100 miles, or about 12 cents a mile. Use your real-world MPG rather than the window sticker figure if you track it.
Multiply the car’s consumption in kWh per 100 miles by your electricity price per kWh. An EV using 30 kWh per 100 miles on home electricity at $0.15 per kWh costs 30 x 0.15, which is $4.50 per 100 miles. Your car’s consumption figure is on its EPA listing and usually in the trip computer; your price per kWh is on your utility bill.
On home charging, nearly always in the US: roughly 4 to 6 cents a mile against 11 to 17 cents for a typical gas car. On public DC fast charging at $0.30 to $0.50 per kWh the gap mostly closes, and an inefficient EV on expensive fast charging can cost the same per mile as an efficient gas car. The honest answer depends on your charging mix, which is why this calculator takes your actual electricity price.
Start with the EPA figure for your exact model, then adjust for your driving. Efficient sedans sit around 25 to 30 kWh per 100 miles, crossovers around 30 to 35, and large trucks 45 to 50 or more. Cold weather, highway speeds, and roof cargo all push consumption up, sometimes by a fifth or more in winter.
Trip mode works backwards from a finished drive. Enter what the trip actually cost in fuel or charging and how many miles it covered, and it returns the cost per 100 miles and per mile for that specific journey, tolls and charging fees included if you fold them into the cost. Fuel mode is for comparing vehicles before you drive; trip mode is for auditing a journey you already made.
Your real MPG, whenever you have it. Short trips, cold starts, and sustained speeds above 60 mph all pull real consumption below the EPA rating, and a comparison built on sticker figures flatters the gas car. If you do not track it, the EPA combined figure is a reasonable starting point, and one tank of manual tracking beats a year of guessing.
A comparison metric from the US Department of Energy: the cost of driving an EV the same distance a gas car travels on one gallon of gasoline. It expresses electricity prices in gallon terms. This calculator does the mirror image, expressing both fuels in cost per 100 miles, which most drivers find easier to budget against because it scales straight to a month or a year of driving.
No. It compares energy cost only, deliberately. Maintenance, insurance, tires, and depreciation are real and often larger than fuel, but they belong to a total cost of ownership analysis, not a fuel comparison. EVs usually win the maintenance comparison too, with no oil changes and far less brake wear, but that saving is separate from the per-100-miles fuel figure.
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References
- Recharged, “Electric Vehicle Cost Per Mile vs Gas”: the per-mile and per-100-miles formulas for both fuels, with worked examples at real-world efficiency and prices. Recharged: EV Cost Per Mile vs Gas. Accessed October 2026.
- Recharged, “Electric Car Price Per Mile: Cost Guide”: comparison table of gas, hybrid, home-charged EV, and fast-charged EV costs per 100 miles. Recharged: Electric Car Price Per Mile. Accessed October 2026.
- EV Gas Calc, “How Much Does It Cost to Charge an EV vs Fill Up with Gas?”: charging levels, home versus public fast-charging prices, and per-mile costs at the national average residential rate. EV Gas Calc: EV Charging Cost vs Gas. Accessed October 2026.
- Choose Energy, “Electricity Rates by State”: state and national average residential electricity prices from US Energy Information Administration data. Choose Energy: Electricity Rates by State (EIA Data). Accessed October 2026.
- Facilities Dive, “Commercial electricity use will likely surpass residential in 2027: EIA”: EIA Short-Term Energy Outlook figures for average US residential electricity prices. Facilities Dive: EIA Residential Electricity Prices. Accessed October 2026.