EV Charging Costs Explained: Home vs. Public

The headline "EVs are cheap to run" is true — but only if you understand where the cheapness comes from. The gap between charging at home overnight and topping up at a public fast charger is enormous, and it's the single biggest factor in whether an EV saves you money.

The one number that matters: cost per mile

Forget price per kWh in isolation; what counts is cost per mile. The formula:

(Electricity price per kWh) ÷ (Miles per kWh) = cost per mile

A typical EV does about 3 to 4 miles per kWh. Plug in your electricity rate and you have your number. Let's compare the two worlds.

Home charging: the cheap world

Charging at home on a standard residential rate — say $0.16 per kWh — an EV doing 3.5 miles/kWh costs about 4.6 cents per mile. On a cheap overnight or time-of-use tariff (some are half the standard rate), it can drop below 3 cents per mile. That's a fraction of what petrol costs — the basis of the whole "EVs are cheaper" case, which we lay out in gas vs electric.

Why home charging wins:

Residential electricity is relatively cheap, especially overnight.
No middleman markup. You pay the utility directly.
Time-of-use tariffs let you charge when power is cheapest and greenest.

Public charging: the expensive world

Public charging splits into two very different tiers:

Level 2 (AC) public chargers — found at workplaces, shops and car parks. Moderately priced, sometimes free, but slow (hours for a full charge).
DC fast chargers — the ones that add serious range in 20–40 minutes. These are the expensive ones, often 2 to 4 times the home rate per kWh, because you're paying for speed, expensive hardware and convenience.

An EV driver who relies mainly on DC fast charging can pay 12–18 cents per mile or more — right up in petrol-car territory. The technology's cost advantage largely evaporates.

The practical rule

Charge at home for daily driving; use fast chargers only for long trips. Do that, and your average cost per mile stays low. Depend on fast chargers for everyday miles, and it won't.

This is why the EV cost case is really a charging-access case. If you have a driveway or reliable overnight charging, EVs are cheap to run. If you'd rely on public fast charging, run the numbers hard before assuming you'll save.

How to keep charging costs down

Charge overnight on a time-of-use or EV tariff. This is the biggest lever by far.
Charge to ~80% for daily use. It's faster, cheaper per useful mile and better for battery life; save 100% for trip days.
Use free or cheap Level 2 where you already park — work, gym, supermarket.
Plan fast-charging stops on long trips rather than defaulting to them. Find chargers on our EV charging map.
Precondition while plugged in in cold weather, so battery heating comes from the grid, not your range.

Bottom line

Home charging is where EVs deliver their famous savings; public fast charging is a convenience you pay a premium for. Know your cost per mile in each mode, lean on home charging for daily driving, and reserve the fast chargers for the road. Model your own savings with the EV savings calculator.

Frequently asked questions

Is it cheaper to charge an EV at home or in public?

Home charging is far cheaper — often around 4–5 cents per mile, or less on an overnight tariff. Public DC fast charging can cost 2–4 times more per kWh, pushing cost per mile close to petrol levels.

How do I calculate my EV charging cost per mile?

Divide your electricity price per kWh by your car's miles per kWh. For example, $0.16 per kWh ÷ 3.5 miles per kWh ≈ 4.6 cents per mile.

Why is public fast charging so expensive?

You're paying for speed, costly high-power hardware, site and grid-connection costs, and convenience. That premium is why relying on fast chargers erodes an EV's running-cost advantage.