Free tool
How fast will your EV actually charge?
Home charging speed is whichever is lower: what your charger can push, or what your car's onboard charger will accept. Usually it's the car — and that's the number nobody tells you at the dealership.
Every charging option, for your car
Bar length is what your car actually draws. Hatched area is capacity you'd pay for and never use.
Show the maths
How this calculator works
There are only two numbers that matter, and the smaller one wins.
1. What your charger can deliver
Australian homes run on a nominal 230 V single-phase supply, or 400 V line-to-line if you have three-phase (AS 60038). Power is simply volts times amps:
- Single-phase: 230 V × amps. A 32 A charger gives 7.36 kW — the "7.4 kW" you see advertised.
- Three-phase: √3 × 400 V × amps. At 16 A that's 11.1 kW; at 32 A it's 22.2 kW.
2. What your car will accept
Every EV has an onboard charger — the box inside the car that converts AC from your wall into DC for the battery. It has a hard kW ceiling, and it's often single-phase only. A car with a 7.4 kW single-phase onboard charger draws 7.4 kW from a 22 kW charger. The other 14.8 kW simply isn't used.
The trap nobody warns you about
An 11 kW three-phase charger is usually 16 A per phase. Plug in a single-phase car and it can only use one of those phases — at 16 A, that's just 3.7 kW. A cheaper 32 A single-phase charger would give the same car 7.4 kW. For that car, the more expensive three-phase unit is literally twice as slow.
3. Losses
Converting AC to DC isn't free. We assume about 90% efficiency at normal normal charger power, dropping to roughly 85% on a 10 A power point, where the car's own electronics eat a bigger share of a small draw. That's why the kilometres-per-hour figure is lower than a naive kW ÷ consumption sum.