EV Home Charger Size Calculator
3.7, 7.4, 11 or 22 kW? Match your wallbox to your battery, driving and overnight window — and don't pay for power your car can't use.
Onboard charger limit: 7.4 or 11 kW typical.
Recommended wallbox
Needed power
Full charge time (7.4 kW)
Don't overspend
Full charge time at each size
| Wallbox | Current | Full charge | Best for |
|---|---|---|---|
| 3.7 kW | 16A 1-phase | Small EV, low mileage | |
| 7.4 kW | 32A 1-phase | Most drivers — the sweet spot | |
| 11 kW | 16A 3-phase | High mileage / 3-phase homes | |
| 22 kW | 32A 3-phase | Only if car supports 22 kW AC |
Frequently asked questions
What size home charger do I need?
For most drivers, a 7.4 kW wallbox fully charges any EV overnight. Choose 11 kW only if you drive 40,000+ km/year or need a full charge in under 4 hours.
Is a bigger charger always better?
No. Your car's onboard charger caps AC power (usually 7.4 or 11 kW), and most drivers never need more than 7.4 kW. A bigger charger costs more and may require a panel upgrade.
What if I drive very long distances daily?
If you drive 300+ km/day and need a full charge in a short overnight window, an 11 kW (or 22 kW if supported) wallbox makes sense.
How do I know my car's max AC power?
Check the onboard charger spec: most cars accept 7.4 kW (single-phase 32A) or 11 kW (three-phase 16A). Your wallbox should match or slightly exceed it.