US EV Mileage & Cost Per Mile Calculator
Calculate your EV’s real home-charging cost per mile — including charging losses — and compare it directly with your gas car.
| Scenario | EV cost / mile | Annual savings |
|---|---|---|
| — | ||
Why your number may differ from other EV calculators
- Charging losses: Energy drawn from the wall is higher than energy stored in the battery. Calculators that ignore this understate real cost by roughly 10–15%.
- Battery-side vs wall-side efficiency: A dash reading of 3.5 mi/kWh is battery-side. EPA kWh/100 mi is wall-side and already includes losses. Mixing the two produces errors.
- Electricity rate type: Your average rate, your marginal tier rate, and a time-of-use off-peak rate can differ substantially. This tool uses the rate you enter.
- Real-world vs EPA efficiency: Temperature, speed, elevation, HVAC use, and driving style can move real-world efficiency well away from EPA figures.
- Public charging: DC fast charging typically costs several times more per kWh than home charging. This tool models home charging only unless you enter a blended rate.
Estimate only. Results are calculated from the values you enter. This tool estimates home-charging energy cost per mile and does not include maintenance, insurance, depreciation, registration fees, incentives, or public charging unless reflected in your inputs. Electricity rates vary by utility, tier, and time of use. Real-world efficiency varies with temperature, speed, and driving style. Not financial or tax advice.
How to Calculate EV Cost Per Mile (And Why Calculators Disagree)
Your EV’s cost per mile is not a single fixed number. It depends on the efficiency you enter, the electricity rate you use, whether charging losses are included, and which side of the charger you’re measuring. That is why two calculators can both be “correct” and still give you results that differ by 20% or more.
This guide walks through the exact formula, the difference between battery-side and wall-side efficiency, why charging losses matter, and how to tell whether a calculator’s answer actually applies to your situation. Every example below is calculated with the same methodology used by our US EV Mileage & Cost Per Mile Calculator, so you can reproduce the numbers yourself.
The Short Answer
Cost per mile for an EV is energy cost divided by distance, adjusted for charging losses. In its simplest form:
EV cost per mile = (electricity rate ÷ miles per kWh) × charging-loss adjustment
For a typical example using an efficiency of 3.5 mi/kWh, a 10% charging loss, and an electricity rate of $0.18/kWh, the calculation is:
- Wall energy per mile = 1 ÷ (3.5 × 0.90) = 0.3175 kWh/mile
- Cost per mile = 0.3175 × $0.18 = $0.0571, or 5.7¢ per mile
- A 30 MPG gas car at $3.50/gal costs 3.50 ÷ 30 = 11.7¢ per mile
The EV is cheaper in this example by about 6¢ per mile. But every number above is an input, not a constant. Change the electricity rate to $0.35/kWh — a rate that exists in parts of the US — and the EV advantage shrinks to roughly 0.6¢ per mile. Change the assumptions again and the advantage can flip.
If you want your own number rather than an example, the calculator linked above will compute it from your inputs. The rest of this article explains what those inputs mean and where the disagreements between calculators come from.
The Formula, Step by Step
Cost per mile always reduces to the same structure: how much wall energy you consume per mile, multiplied by what you pay per unit of that energy. The complication is that EV efficiency is reported in several different units, and they are not interchangeable without a conversion.
Battery-side efficiency (mi/kWh)
If you have a miles-per-kWh figure — from your vehicle’s dashboard, from a trip computer, or from a manual calculation — that reading is battery-side. It describes how far the vehicle travels per unit of energy stored in the battery. To convert it into wall energy, you have to account for the energy lost during charging:
Wall kWh per mile = 1 ÷ (mi/kWh × (1 − charging loss))
EV cost per mile = wall kWh per mile × electricity rate
Charging loss is typically expressed as a decimal. A 10% loss means 0.90 of the wall energy reaches the battery, so you divide by 0.90. If you skip this adjustment, your cost per mile will be understated by roughly the loss percentage.
Wall-side efficiency (kWh/100 mi)
The EPA’s kWh/100 mi rating is wall-side: it is measured at the charger, so it already includes charging losses. You do not need to apply a loss adjustment again. Applying one produces a double-counted and too-high cost:
EV cost per mile = (kWh per 100 miles ÷ 100) × electricity rate
This is the most common error we see in user-submitted comparisons: someone takes an EPA kWh/100 mi figure, applies a 10% loss on top, and concludes that EVs cost more than they do. The EPA figure is already the wall figure.
Gas comparison
The gas side is simpler:
Gas cost per mile = gas price ÷ gas car MPG
For a meaningful comparison, use your actual gas price and the MPG of the vehicle you would otherwise be driving — not a national average and a generic 30 MPG. A 22 MPG truck and a 45 MPG hybrid will give very different breakeven points against the same EV.
Battery-Side vs Wall-Side Efficiency
The single biggest source of disagreement between EV cost calculators is that they mix these two measurement bases. Many EV dashboards show battery-side mi/kWh. The EPA shows wall-side kWh/100 mi. If you enter one into a calculator that expects the other, the result will be off by the charging-loss percentage — typically 10% to 15%, which is enough to change a decision at the margin.
| Metric | What it measures | Side | What “better” looks like |
|---|---|---|---|
| mi/kWh | Miles travelled per kWh | Battery | Higher is better |
| kWh/100 mi | kWh consumed per 100 miles | Wall (EPA) | Lower is better; already includes losses |
| Wh/mi | Wh consumed per mile | Battery (usually) | Lower is better |
| MPGe | Miles per gallon equivalent | Test cycle | Higher is better; useful for comparison only |
When in doubt, look at where the number came from. A dash display is almost always battery-side. The EPA window sticker and fueleconomy.gov are wall-side. If a calculator asks you for “efficiency” without telling you which side it expects, that is a warning sign.
Charging Losses: The Variable Most Calculators Miss
Charging is not perfectly efficient. Some energy drawn from the wall is lost as heat in the charger, the onboard conversion equipment, and the battery itself. For Level 1 and Level 2 home charging, the loss is commonly cited in the 10–15% range, though it varies by equipment, temperature, and state of charge. A 10% assumption is a reasonable starting point for most home charging scenarios; users with older or particularly inefficient equipment may want to test their own figure.
Why this matters for cost per mile:
- If your electricity rate is $0.18/kWh and you assume no loss, a 3.5 mi/kWh EV appears to cost about 5.1¢ per mile.
- Include a 10% loss and the same vehicle costs about 5.7¢ per mile.
- At 15% loss, it costs about 6.1¢ per mile.
The absolute difference is small per mile, but it compounds across tens of thousands of miles and across years of ownership. It is also enough to change the ranking in a close EV-vs-gas comparison. A calculator that omits charging losses is not necessarily wrong — it is measuring a narrower concept — but it is measuring something different from what most users think they are getting.
One important exception: the EPA kWh/100 mi figure already includes charging losses, so when you use that metric, do not apply a loss adjustment again.
Why Your Number May Differ from Another Calculator
If two calculators give you different results for what seems like the same EV, here are the four most common reasons.
Charging losses
Some calculators model them; some do not; some model them at a fixed percentage; some let you set the percentage. If two tools produce numbers that differ by roughly 10%, check whether one of them is applying a loss and the other is not. This is the first thing to verify.
Rate type (average, marginal, or time-of-use)
Electricity rates for a home are not a single number. There is the average rate you see on your bill, the marginal rate you pay on the next kWh you use (which can be in a higher tier), and — if you are on a time-of-use plan — the off-peak or super-off-peak rate that applies when you charge overnight. A calculator using a state average is answering a different question from a calculator using your marginal off-peak rate. For EV charging, the marginal off-peak rate is often the most relevant figure, because you are typically adding load rather than replacing existing consumption.
EPA vs real-world efficiency
The EPA test cycle produces a standardized efficiency rating. Real-world efficiency varies with temperature, speed, terrain, HVAC use, tire pressure, and driving style. On highways at high speed, or in cold weather, real-world efficiency can be meaningfully lower than the EPA figure. A calculator that uses the EPA number is giving you a test-cycle answer; a calculator that uses your dash reading is giving you a real-world (battery-side) answer. Neither is wrong — they are answering slightly different questions.
Public charging
If you charge on public networks, the cost per kWh is often several times the home rate. A pure home-charging calculation will understate your true cost if a significant share of your charging is on public DC fast chargers. Calculators that let you enter a blend of home and public charging will give you a more complete picture; calculators that assume 100% home charging will give you an optimistic floor.
State-Level Context
Electricity rates vary dramatically across the United States. Some states have residential rates well below the national average, and some — notably Hawaii and parts of California and the Northeast — have rates several times higher. A cost-per-mile comparison that uses a national average rate will not tell you whether an EV makes sense where you actually live.
Use your own utility bill, not a state or national average. If you want to model a different location before moving, use the current residential rate for that area from the US Energy Information Administration (EIA), and note the month and year the rate reflects — the EIA updates state-level rates periodically. Gas prices also vary by region, so the comparison inputs should reflect the same geography.
For users in states with high residential rates and low gas prices, the EV advantage can be quite small — or, in extreme cases, disappear. This is not a failure of EV technology; it is the arithmetic of energy prices. Being honest about that range is more useful than repeating a generic “EVs are much cheaper to run” claim.
Worked Examples
The examples below are illustrative, calculated with the methodology described above. They are not claims about current US averages. Substitute your own efficiency, rate, gas price, and MPG to get a result that applies to you.
Average-mileage driver
Inputs: 3.5 mi/kWh battery-side, 10% charging loss, $0.18/kWh electricity, 12,000 miles/year, 30 MPG gas car at $3.50/gal.
- EV cost per mile: 5.7¢
- Gas cost per mile: 11.7¢
- Annual electricity cost: about $684
- Annual savings vs gas: about $715
High-cost electricity driver
Same EV efficiency and mileage, but electricity at $0.35/kWh — a rate present in parts of the US with high residential electricity.
- EV cost per mile: 11.1¢
- Gas cost per mile: 11.7¢
- Annual electricity cost: about $1,333
- Annual savings vs gas: about $72
At these inputs, the EV is still cheaper, but only marginally. At $0.40/kWh or with a more efficient gas car, the EV can cost more to run per mile than gasoline. This is the scenario most EV cost calculators hide.
High-mileage driver
Same inputs as the first example, but 20,000 miles/year.
- Annual electricity cost: about $1,140
- Annual savings vs gas: about $1,192
Higher mileage amplifies whatever per-mile advantage or disadvantage exists. It also makes charging losses a more meaningful dollar figure — at 20,000 miles, a 5% difference in assumed loss is worth tens of dollars per year.
Sensitivity and Break-Even
The output of a cost-per-mile calculation is a point estimate. What most users actually want is the range and the tipping point. Two pieces of analysis are worth knowing.
Break-even electricity price is the rate at which your EV’s cost per mile equals your gas car’s cost per mile. Above that rate, gas is cheaper; below it, the EV is cheaper. It is calculated as:
Break-even rate = (gas price ÷ MPG) ÷ wall kWh per mile
For the first example above, the break-even rate is about $0.367/kWh. If your electricity rate is below that, the EV wins; above that, the gas car does.
Break-even gas price is the inverse: the gas price at which your EV and gas car cost the same per mile. It is calculated as:
Break-even gas price = EV cost per mile × MPG
For the first example, the break-even gas price is about $1.71/gal. Above that, the EV is cheaper; below it, the gas car wins.
These two figures are more useful than a single cost-per-mile number, because they tell you how much room there is for prices to move before the conclusion flips. A calculation where the EV barely wins is fragile; a calculation with a wide margin is robust.
Limitations
Cost per mile — as calculated here — is an energy cost. It is not the total cost of owning or operating an EV. It excludes maintenance, tires, insurance, depreciation, registration fees, incentives, and public charging unless you specifically include them. For a full ownership comparison, use a total cost of ownership calculator rather than a cost-per-mile calculator.
Additionally:
- Real-world efficiency varies. EPA ratings and dash readings are both estimates of what a vehicle does under specific conditions. Cold weather, high speeds, elevation, and driving style can move real-world efficiency outside the ranges described here.
- Electricity rates vary by utility and tier. Two users in the same state can pay different rates depending on their utility, plan, and consumption tier.
- Charging losses vary. The 10–15% range is a common planning assumption, not a universal constant. Users with specific equipment and metering can measure their own figure.
- Gas prices are volatile. A comparison built on today’s gas price may not hold in six months.
- Tax and incentive treatment is out of scope. State and federal incentives change, and this calculation does not attempt to model them. Verify current rules from the relevant authority before using any incentive in a decision.
Frequently Asked Questions
How do I calculate cost per mile for an EV?
Convert your efficiency to wall energy per mile, then multiply by your electricity rate. If you have battery-side mi/kWh, divide by (1 − charging loss) first. If you have EPA kWh/100 mi, divide by 100. Then multiply by your rate. See the formula section above for the full step-by-step.
What is the formula for EV cost per mile?
EV cost per mile = (1 ÷ (mi/kWh × (1 − loss))) × rate, for battery-side efficiency. Or, for wall-side efficiency: (kWh/100 mi ÷ 100) × rate. The two formulas are equivalent — they just start from a different measurement basis.
Does the EPA kWh/100 mi figure include charging losses?
Yes. The EPA’s kWh/100 mi rating is measured at the wall, which means charging losses are already included. If you use this metric, do not apply a loss adjustment a second time.
Why is my calculated cost per mile different from an online calculator?
The most common reasons are: (1) one calculator applies a charging-loss adjustment and the other does not; (2) one uses a state or national average electricity rate and the other uses your actual rate; (3) one uses EPA test-cycle efficiency and the other uses real-world (dash) efficiency; (4) one assumes 100% home charging and the other blends in public charging. Compare the assumptions before comparing the results.
Should I use battery-side or wall-side efficiency?
Use whichever number you actually have. If you are reading mi/kWh or Wh/mi from the dashboard, that is battery-side and you need to apply a loss adjustment. If you are reading kWh/100 mi from the EPA or a window sticker, that is wall-side and no loss adjustment is needed. The calculator should ask which you are entering, or the input should be labeled.
How do I convert Wh/mi to mi/kWh?
Divide 1,000 by the Wh/mi figure. For example, 250 Wh/mi = 1000 ÷ 250 = 4.0 mi/kWh. To convert kWh/100 mi to mi/kWh, divide 100 by the kWh/100 mi figure.
What is the break-even electricity price for an EV?
It depends on your gas comparison. The break-even rate is (gas price ÷ MPG) ÷ wall kWh per mile. For a 30 MPG gas car at $3.50/gal and an EV using 0.3175 wall kWh/mile, the break-even rate is about $0.367/kWh. Above that rate, the gas car is cheaper to run; below it, the EV is.
Does this calculation include insurance, maintenance, or depreciation?
No. This is an energy-only cost-per-mile calculation. Insurance, maintenance, tires, depreciation, and registration are separate. For a full ownership comparison, use a total-cost-of-ownership tool rather than a cost-per-mile tool.
Sources and Methodology
The calculations in this article use standard arithmetic. The inputs — efficiency, electricity rate, gas price, MPG, charging-loss percentage, and annual mileage — come from the user. No input is treated as a universal constant.
For inputs that users typically source externally, the following authoritative references are the appropriate places to verify current figures:
- Electricity rates: US Energy Information Administration (EIA) publishes state-level residential electricity prices. Verify the current rate for your state and note the month and year it reflects.
- Gas prices: EIA and other authoritative sources publish regional and state gas prices. Use a current figure and the same geography as the electricity comparison.
- Vehicle efficiency (EPA): The EPA’s fueleconomy.gov provides official kWh/100 mi and MPGe ratings for US-market vehicles. These are wall-side figures and already include charging losses.
- Charging context: The US Department of Energy’s Alternative Fuels Data Center provides background on charging levels, connectors, and station types.
- Mileage reimbursement (if applicable): The IRS publishes an annual standard mileage rate for business use. The current-year figure should be verified from the IRS directly, not assumed from a prior year.
This article deliberately does not cite specific current electricity rates, gas prices, IRS rates, or incentive amounts, because those figures change and a published number would quickly become misleading. Use the sources above to verify the current figure for your situation.
Calculate Your Own Cost Per Mile
The formula is simple, but the variables are not. Our US EV Mileage & Cost Per Mile Calculator lets you enter your own efficiency (battery-side or wall-side), your electricity rate, your charging-loss assumption, your annual mileage, and your gas comparison, and returns cost per mile, annual savings, and break-even thresholds. It is built around the same methodology described here, so the output matches the explanation.
If you want to go further — for example, to see what your EV charging cost adds to your monthly electricity bill, or to compare the full ownership cost of an EV against a gas car — the cost-per-mile calculation is one input among several. Use it as a starting point, not as a complete ownership answer.
Related EV tools
- Marginal-Rate EV Charging Cost Calculator — estimate what your EV charging actually adds to your monthly bill.
- EV Insurance & Total Cost of Ownership Calculator — compare full ownership costs, not just energy.
- EV Range Calculator by Temperature — see how cold and heat affect real-world range.
- EV Battery Aging Calculator — project battery health and remaining capacity over time.
State-level residential electricity prices are published by the U.S. Energy Information Administration (EIA). Use the current table for your state and note the release date — the EIA updates this dataset annually, and a rate from a prior year can materially change the result.
Official wall-side efficiency ratings — including kWh/100 mi and MPGe — are published on fueleconomy.gov, the EPA’s fuel economy database. These figures already include charging losses, so they should not receive a second loss adjustment.
For charging infrastructure data, station locators, and vehicle comparison tools, the U.S. Department of Energy’s Alternative Fuels Data Center (AFDC) is the primary federal resource. Its tools are useful for verifying charging context and comparing vehicle costs.
If you are calculating business-use reimbursement, the current standard mileage rate is published by the Internal Revenue Service (IRS). The IRS rate applies to fully electric and hybrid vehicles as well as gasoline vehicles. Verify the current-year figure directly — the rate is adjusted annually.
Regional and national gasoline prices — including PADD-level breakdowns — are published in the EIA’s Weekly Retail Gasoline and Diesel Prices report. Use the same geography and time period as your electricity-rate input for a fair comparison.