EV vs Gas Cost Calculator — What You Actually Save Per Month
This is the one calculator on the US site with no blank fields, and the reason is that both numbers it needs are published nationally by the same agency. EIA reports retail gasoline weekly and residential electricity monthly, so the comparison can be made honestly without asking you for anything.
At the August 2026 pump average of $4.079 a gallon against the May 2026 residential average of 18.44 cents a kWh, the gap is wide — roughly a quarter of the cost per mile. Charging from your own roof narrows it further, toward the cost of the panels rather than the cost of the kWh.
Every field below is editable, and every default carries its source and date on the field itself — the defaults are a starting point, not a claim about your bill. We sell no hardware and take no installer commission; see how we verify.
6 fields on this page ship blank, on purpose
No source we can cite publishes these figures for US, so the fields start empty rather than pre-filled with something plausible. The calculator prints no result until you supply your own.
- What one exported unit is worth ($/kWh) — There is no national US export rate, so there is nothing to default to. Compensation is set state by state and increasingly utility by utility: some states still credit an exported unit at the full retail rate (true net metering), others pay an export rate well below retail (California’s NEM 3.0 is the largest example), and a few offer no compensation at all. A single national number would be wrong in most of the country. Look your state up on DSIRE, then type the rate your own utility actually pays.
- Units per month per installed kW — No figure is printed here for two reasons. NREL publishes the authoritative per-location tool — PVWatts, at pvwatts.nrel.gov — but every NREL host was unreachable from our research session on 9 August 2026, and we do not publish numbers we could not read. It is also the wrong shape for a national default: output per installed kW varies by about half again between the cloudiest and the sunniest states, so a US average would misdescribe most roofs. Run PVWatts for your own address, divide the annual kWh by 12 and by the system kW, and type it in.
- Battery cost ($ per kWh) — No US source we can cite publishes a residential battery product price per kWh. Berkeley Lab publishes paired PV+storage pricing per kW of PV capacity — a median $5.3/W cash against $3.5/W for stand-alone PV — which is a whole-system installed price, not a battery price, and roughly 90% of that paired sample is California. Dividing the one by the other would turn a Californian system premium into a national module price. Type the per-kWh figure from your own quote.
- Battery modules added to a new system ($ per kWh) — Blank for the same reason as the battery cost above: Berkeley Lab prices paired systems per kW of PV, not storage per kWh, and its paired-pricing sample is overwhelmingly Californian. For scale while you get a quote, its median residential battery in 2024 was 13.5 kWh at a 2-hour duration.
- Price of one panel ($) — US residential solar is sold as an installed system, not as panels — the per-watt prices published for this market are whole-system prices including labour, inverters, permitting and margin. There is no verified national retail price for a single module, and quoting a distributor or marketplace listing as one would misstate what an American buyer actually pays. Use the installed cost per kW above instead.
- Usable kWh per panel per day — Follows directly from the generation figure above, which we could not source because every NREL host was unreachable on 9 August 2026. Run PVWatts for your own address with your panel count, then divide the daily kWh by the number of panels.
Petrol: $73/month · EV: $19/month
Monthly saving: $53 ($642/year). Charging from rooftop solar pushes the EV cost toward $0/mile.
How this calculator works — the actual arithmetic
- Gas cost = miles per month ÷ your car’s MPG × the pump price per gallon.
- EV cost = miles per month ÷ 100 × kWh per 100 miles × your electricity rate.
- The pump price defaults to $4.079 a gallon — EIA’s US regular-grade retail average for the week ending 3 August 2026, all taxes in. The electricity rate defaults to 18.44 cents, EIA’s US average residential price for May 2026.
- Both are national averages and both are editable. Regional pump prices that week ran from $3.60 on the Gulf Coast to $5.13 on the West Coast, and residential electricity ranges from about 11 cents to over 40 depending on the state, so your two numbers are better than these two.
Worked example — 500 miles a month at the national averages
Every input below is either an EIA figure quoted with its date or the calculator’s own starting value, and every output is what the calculator prints for those inputs.
| Miles per month | 500 |
|---|---|
| Pump price (EIA, week ending 3 Aug 2026) | $4.079 / gallon |
| Gas car efficiency | 28 MPG |
| EV consumption | 21 kWh / 100 miles |
| Electricity rate (EIA, May 2026 US residential average) | $0.1844 / kWh |
| Gas | $73 / month |
|---|---|
| EV | $19 / month |
| Monthly saving | $53 |
| Annual saving | $642 |
Where these numbers come from
The pump price and the electricity rate are EIA’s own published national averages, listed with their URLs and access date under every calculator on this site. The 28 MPG and 21 kWh/100 miles are the calculator’s editable starting values, not claims about your car — change both to yours. EV vs gas: the total cost extends this past fuel.
Sources for this market’s defaults
- EIA — Electric Power Monthly, Table 5.6.A, Average Price of Electricity to Ultimate Customers by End-Use Sector (US Total residential 18.44 cents/kWh, May 2026; 17.37 in May 2025) accessed 2026-08-09
- EIA — Gasoline and Diesel Fuel Update (US regular gasoline $4.079/gallon, week ending 3 August 2026, all taxes included) accessed 2026-08-09
- Berkeley Lab (LBNL) — U.S. Distributed Solar and Storage, 2025 Data Update, October 2025 (2024 installs: residential stand-alone PV median installed price $3.5/W cash and $4.7/W loan in 2024$/Wdc, gross of incentives; median residential battery 13.5 kWh) accessed 2026-08-09
- DSIRE (NC Clean Energy Technology Center) — Database of State Incentives for Renewables & Efficiency. The reason the export credit ships blank: net metering and net billing are state-level program types here, not a national rate. accessed 2026-08-09
What this calculator does not know
- Fuel and electricity only. Purchase price, depreciation, maintenance, insurance and incentives are all outside this sum.
- Both defaults are national averages. Gas is weekly and moves; electricity is monthly and varies roughly four-fold across states.
- Home charging at a flat rate. A time-of-use overnight window is cheaper; DC fast charging is two to three times dearer.
- Charging losses between the wall and the battery are not modelled, so the real EV figure is a little higher than printed.
Frequently asked
Is it cheaper to charge an EV than to buy gas?
At national average prices, substantially. Driving 500 miles a month in a 28 MPG gas car costs about $73 in fuel at $4.079 a gallon; the same 500 miles in an EV using 21 kWh per 100 miles costs about $19 at the 18.44 cent average residential rate. That is roughly $53 a month, or $642 a year.
What is the average price of gas in the US right now?
EIA put the US regular-grade retail average at $4.079 a gallon for the week ending 3 August 2026, including all taxes. It is a weekly series, so it moves; regional averages that same week spanned $3.60 on the Gulf Coast to $5.13 on the West Coast.
What does it cost to charge an EV at home?
At the US average residential rate of 18.44 cents per kWh, an EV using 21 kWh per 100 miles costs about $3.87 per 100 miles. A time-of-use plan with an overnight EV window is usually cheaper than that flat average, and DC fast charging on the road is typically two to three times it.
Does this account for the tax credit or maintenance?
No. This compares fuel against electricity and nothing else — no purchase price, no maintenance, no insurance, no incentives. Our EV-vs-gas total cost guide runs the full comparison; this page is deliberately just the running-cost line.
Guides that explain the numbers
Fuel is one line of it; this guide runs the rest.
What it costs to charge an EVHome, public and fast charging priced separately.
Playing time-of-use ratesThe overnight window that beats the flat average used here.
Run these next
Panels needed to cover your daily miles. Bring the daily kWh one panel makes where you live — PVWatts gives it in a minute.
Solar system size calculatorTurn your monthly kWh into a kW system size and a cost band built on Berkeley Lab’s medians. Bring one number: what a kW produces on your roof.