ChargeWise

EV Home Charging Cost Calculator

What it really costs to charge your EV in the driveway — per week, per year, and per mile.

Miles driven per week

Vehicle efficiency (mi/kWh)

Electricity price ($/kWh)

Charging losses (%)

Charged from surplus solar (%)

Weekly charging cost

$9.52

Annual cost: $495
Cost per mile: $0.048
Grid energy / week: 63.5 kWh

What you entered

Miles / week: 200Efficiency: 3.5 mi/kWhElectricity: $0.15/kWhCharging losses: 10%Solar share: 0%

1
Energy to move the car
200 mi ÷ 3.5 mi/kWh= 57.1 kWh
2
Add charging losses
57.1 ÷ (1 − 10%)= 63.5 kWh drawn
3
Grid energy after surplus solar
63.5 × (1 − 0%)= 63.5 kWh
4
Weekly charging cost
63.5 kWh × $0.15/kWh= $9.52
5
Annual cost and cost per mile
$9.52 × 52 • $9.52 ÷ 200 mi= $495/yr • $0.048/mi

Result

Weekly charging cost: $9.52

Charging at home costs about $9.52/week ($495/year), or $0.048 per mile at these settings.

Home charging cost by electricity tariff, at 200 miles a week

A car driven 200 miles a week at 3.5 mi/kWh needs 57.1 kWh in the battery, which becomes 63.5 kWh drawn from the wall once 10 percent AC charging losses are added, with no solar. Only the tariff changes down the rows.

Electricity tariff	Price ($/kWh)	Weekly cost	Annual cost	Cost per mile
Dedicated overnight EV rate	$0.08	$5.08	$264	$0.025
Cheap off-peak window	$0.10	$6.35	$330	$0.032
Low standard rate	$0.12	$7.62	$396	$0.038
Typical flat residential rate	$0.15	$9.52	$495	$0.048
Above-average flat rate	$0.18	$11.43	$594	$0.057
High standard rate	$0.22	$13.97	$726	$0.070
Time-of-use peak rate	$0.28	$17.78	$924	$0.089
Expensive peak window	$0.35	$22.22	$1,156	$0.111
Very high peak rate	$0.45	$28.57	$1,486	$0.143

Your tariff swings the annual bill by more than five times across this table for identical driving, which is why scheduling charging into an off-peak or dedicated EV window is worth more than any other change. Two things shift the whole column: efficiency, since cold weather and sustained high speeds can cut real mi/kWh by 20 to 30 percent and raise every figure proportionally, and surplus solar, which removes its share of the grid energy before the price is applied. Charging losses of 8 to 15 percent are real but small next to the tariff. Illustrative only. Use your own tariff, your own weekly miles and your own measured mi/kWh.

An EV home-charging cost calculator turns the two things you actually control — how far you drive and what you pay for electricity — into the real weekly and annual cost of charging your electric car at home. Public fast-charging headlines get the attention, but for most owners the overwhelming majority of charging happens overnight in the driveway or garage, where the price per kilowatt-hour is far lower and entirely predictable. This tool models that home-charging reality rather than a worst-case rapid-charger rate.

The calculation starts from your weekly mileage and your car's efficiency, expressed in miles per kilowatt-hour. A typical modern EV manages 3 to 4 mi/kWh in mixed driving, though cold weather, motorway speeds, and heavy loads pull that figure down. Dividing weekly miles by efficiency gives the energy that ends up in the battery. Because AC home charging is not perfectly efficient — some energy is lost as heat in the charger, cabling, and the car's onboard converter — the calculator adds a charging-loss allowance (usually 8-15%) to find the energy actually drawn from the wall. If you generate your own solar power, the surplus-solar percentage removes that share from your grid bill, since sunlight you would otherwise export is effectively free to divert into the car.

Multiplying the remaining grid energy by your electricity price gives the weekly cost, which is then scaled to an annual figure and broken down into a cost per mile so you can compare it directly against the pump price of a petrol or diesel car. The single biggest lever on the result is your tariff: charging on a dedicated off-peak or EV electricity plan, often a third of the daytime rate, can dramatically cut the annual cost. Scheduling charging into those cheap windows, and topping up from surplus solar where possible, is what separates a genuinely cheap EV from one that costs almost as much to run as the car it replaced. Adjust the inputs to match your own driving, tariff, and solar setup and watch the numbers update instantly.

Why your tariff matters more than your car

The difference between charging on a flat daytime rate and a dedicated off-peak EV tariff can be 3× on price per kWh. A car that costs $900/year to charge at the standard rate might cost only $300/year on an overnight plan for the same miles. Before optimizing anything else, check whether your utility offers a time-of-use or EV tariff and schedule charging into the cheap window.

Charging losses are real but small

AC home charging is typically 85-92% efficient — the rest is lost as heat in the charger, cables, and the car's onboard converter. That means you pay for roughly 8-15% more electricity than actually reaches the battery. It's worth including for an honest estimate, but it's a rounding error next to the impact of your tariff and your real-world efficiency.

Frequently asked questions

I drive 200 miles a week in an EV that does 3.5 mi/kWh — what does home charging cost?

About 57 kWh reaches the battery; with 10% charging losses you draw ~63 kWh from the grid. At $0.15/kWh that's roughly $9.50/week, about $495/year, or ~4.8 cents per mile — well below the per-mile fuel cost of most petrol cars.

What's a realistic mi/kWh figure to use?

Most modern EVs average 3-4 mi/kWh in mixed driving. Efficient small EVs can exceed 4; large SUVs and pickups may be 2-2.5. Cold weather and sustained high-speed driving can cut real-world efficiency by 20-30%, so use a lower figure for winter estimates.

Does charging from my solar panels make it free?

Only the share you enter as surplus solar is treated as free, because that's energy you'd otherwise export (often for a low feed-in rate). Charging entirely from surplus daytime solar can drop your marginal charging cost close to zero, but most home charging happens overnight, so a realistic solar share is usually well under 100%.

How is this different from the EV vs Gas calculator?

This calculator focuses only on the home electricity cost of charging, including losses and surplus solar. The EV vs Gas calculator compares an EV's total fuel cost against a petrol car's to show annual savings. Use this one to pin down your charging cost, then that one to compare against a specific gas vehicle.