What goes into a total, and what it leaves out
Five lines carry almost all of the difference between two vehicles over a few years: what the vehicle loses in value, what it costs to move, what the state charges to keep it registered, what an insurer charges to cover it, and what keeping it running costs. This page adds those for both vehicles across a period you choose and subtracts one from the other. Everything else — charger installation, financing interest, the time cost of charging on a road trip, local perks such as toll discounts or carpool-lane access where they exist — is left out deliberately, because it varies so much by household and location that a default would be misleading. Add whatever applies to you on top.
The energy comparison is a rate comparison
A gasoline vehicle at 30 MPG with fuel at $3.50 spends 11.7 cents a mile. An electric vehicle at 3.5 miles per kWh charging at 16 cents a kWh spends 4.6 cents a mile. Over 12,000 miles that is $1,400 against $549, and the gap is where the entire argument for the more expensive vehicle lives.
But shift the electricity rate and the picture changes quickly. Charge exclusively on public DC fast charging at 45 cents and the same vehicle is at 12.9 cents a mile, which is worse than the gasoline car. Charge overnight at an off-peak rate and it drops below 3 cents. The share-of-public-charging field exists because most people are somewhere between those extremes, and where you sit on that scale matters more than the vehicle you pick.
The same volatility applies on the other side. Gasoline moves week to week, differs by more than a dollar a gallon between states, and has done both in living memory. There is no fair fixed number for either fuel, which is why both are fields.
Resale is the largest line, and the least certain
Value lost usually exceeds every running cost combined, and the two resale percentages therefore swing the total harder than any other input. They are also the numbers nobody can know in advance. Electric vehicle resale has been particularly unsettled, moving with incentive changes, battery and charging improvements between model generations, and buyer sentiment about battery life. A ten-point change in either percentage moves a $40,000 vehicle by $4,000, which is more than several years of the energy saving.
The practical response is to run the comparison twice with pessimistic and optimistic resale assumptions and see whether the conclusion survives both. If it flips, the honest answer is that the comparison does not resolve, and the decision should be made on the things you can actually observe: whether you can charge at home, what your commute looks like, and how the vehicles drive.
Reading the break-even
The break-even mileage answers a narrow question: holding everything else in the table constant, how many miles a year would you need to drive for the energy saving to close whatever gap the fixed costs opened. Below it, the cheaper vehicle to buy wins; above it, the cheaper vehicle to run wins. It goes to infinity if the EV also costs more per mile — which happens when public charging dominates — and it disappears entirely if the EV is already ahead before any driving, which happens when incentives are large and the price gap is small.
One structural point worth keeping in view: because most of the EV's advantage arrives per mile and most of its disadvantage arrives up front, high-mileage drivers are the ones the arithmetic favours, and a household that drives 5,000 miles a year is unlikely to recover a large price premium on running costs no matter what the rates do.
Fees, taxes and everything else this page refuses to assume
Nothing on this page knows what you pay. Fuel prices, electricity rates, registration fees, personal property tax on vehicles, inspection charges, insurance premiums and tolls all differ by state, county, vehicle and driver, and several of them move month to month. Every one of them is a field you fill in, and the output is only as good as what you put there. That includes the registration fields, where several states now levy an additional annual charge on electric vehicles to substitute for fuel tax they no longer collect, at amounts that differ substantially and change with legislation. It includes insurance, where the premium difference between two specific vehicles for one specific driver is knowable only by getting both quotes. And it includes incentives, where eligibility depends on the vehicle, the buyer's circumstances and the jurisdiction, and where the rules have changed repeatedly. Put in what you have actually confirmed, leave the rest at zero, and the comparison will be worth something.
Questions people ask
Should I put the incentive in the price field or the incentive field?
The incentive field, so the two are visible separately. Keeping them apart matters because they behave differently: the price is what determines the vehicle's position in the used market later, while the incentive is a one-time reduction in what you paid. This page deducts the incentive from the purchase price when computing value lost, but calculates resale as a percentage of the pre-incentive price, which is the convention that treats an incentivised purchase fairly. Only enter an amount you have confirmed you will actually receive — some incentives are point-of-sale reductions, some are claimed later and depend on your tax situation, and eligibility can depend on the vehicle, where it was assembled, its price, and your income. An incentive you assume and do not receive is the single easiest way to make this comparison wrong by thousands of dollars.
How do I estimate my share of public charging?
Think about where the car sleeps rather than where it drives. Someone with a driveway or garage and a circuit for a charger will do the overwhelming majority of charging at home, with public sessions confined to road trips — commonly ten to twenty percent of the miles or less. Someone in an apartment or on street parking may have no home option at all and could be at eighty or a hundred percent, at a rate two or three times higher. Workplace charging, where it exists and is free or cheap, shifts things again. This single field is often the difference between an electric vehicle being much cheaper to run and being more expensive, so it deserves more thought than most of the others. If you are unsure, run the comparison at both ends of your plausible range.
Why is home charger installation not in the calculation?
Because the range is too wide for a default to be anything but misleading. If there is spare capacity in the panel and a short run to where the car parks, the job is modest. If the panel is full, the service needs upgrading, the run is long, or the parking is detached from the house, the cost can be several thousand dollars and may involve utility work. Some utilities offer rebates that offset part of it and some do not. Get a quote for your specific situation and add it to the EV column as a one-off — it does not recur, so on a longer holding period it matters proportionally less, which is itself a reason to keep it visible rather than buried in an average.
Does the comparison work for a hybrid?
Yes, and it is a comparison worth running, because hybrids frequently beat both alternatives in the middle of the mileage range. Put the hybrid in the gasoline column with its actual observed economy, which will be far higher than a conventional equivalent, and its actual purchase price. What you will usually see is that the energy gap against the electric vehicle narrows sharply while the purchase price gap stays, which pushes the break-even mileage up considerably. Plug-in hybrids are harder to model here, because they run on grid electricity for part of their miles and gasoline for the rest, and the split depends entirely on trip lengths and charging habits. For those, the closest honest approach is to estimate the electric and gasoline mileage separately and price each on the fuel calculator.