EV Charger Calculator

Work out how many km/h you'll get charging at home, compare it to public fast charging, and check what your state requires for installation.

How this works

How fast an EV charges at home comes down to two things: how much power your circuit can deliver (phase and breaker size), and how much your car's onboard charger can actually accept — often less than the circuit could give it. This works both through to a realistic km-per-hour figure, not just the theoretical max off your switchboard. (Assumes a typical mid-size EV at ~18kWh/100km — your actual car may be a bit more or less efficient.)

Your home supply

Single-phase or three-phase, and the breaker size feeding the charger.

Standard Australian breaker sizes — pick whichever your circuit is (or would be) wired for. 10A is a standard power point, the kind a portable "trickle" charger plugs into.

Your car's onboard charger

Even on a big circuit, your car can only pull as much AC power as its onboard charger allows.

Readout

Single-phase · 32A circuit

37 km/h

charging rate at 6.6 kW to the battery

Circuit capacity7.4kW

Vehicle onboard charger cap7.4kW

Effective charging power7.4kW

After ~10% charging losses6.6kW

How this compares to public fast charging:

Typical public DC fast charger50kW → 278km/h

High-power public DC charger150kW → 833km/h

Tesla Supercharger (V3, peak)250kW → 1,389km/h

Public DC fast charging bypasses your car's onboard AC charger entirely, and most EVs can accept far more DC power than AC — hence the big jump. These figures are indicative only: real DC charging speed depends heavily on your specific car, and tapers off a lot once the battery's past about 80%.

Why your car might not hit the circuit's full rate: plenty of EVs sold in Australia only accept single-phase AC even when plugged into a three-phase circuit, capping them around 7.4kW regardless of what the wall can deliver. Others accept three-phase but only up to 11kW, not the full 22kW a 32A three-phase circuit could technically supply. Always check your car's spec sheet before assuming a bigger circuit means a faster charge.

10A / trickle charging: handy in a pinch or for a plug-in hybrid, but it's sharing a standard household circuit with everything else on it — not something to rely on for daily high-km driving. Portable EVSE units are often set to draw a bit under 10A for safety on a continuous load, so real-world speed can be slightly under the numbers shown here.

Installation: EV chargers must be installed by a licensed electrician on a dedicated, individually protected circuit, compliant with AS/NZS 3000. Above certain breaker sizes, your electricity network operator (DNSP) may also need to be notified or asked to approve the connection — see the state-by-state breakdown below.

Installation rules by state

Every state handles network approval for home EV chargers a bit differently — mostly around what happens once you go past a standard powerpoint. These are simplified summaries of publicly available network operator guidance. Rules in this space move fast and get updated — always confirm current requirements with your electrician or local network operator (DNSP) before installing anything bigger than a standard circuit.

Under the Queensland Electricity Connection Manual (QECM v4), a dedicated single-phase EV charger drawing more than 20A needs "active device management" before it can be connected — a network device, a load-control tariff, or a dynamic connection. A charger kept at 20A (4.6kW) or under doesn't trigger this.

Three-phase changes the picture: a dedicated charger up to 22kW (32A), connected and switched across all three phases at once, is exempt from the device-management requirement entirely. It's a real reason people go three-phase for EV charging in Queensland where it's available.