AusElectrical.tools
Home/Calculators/EV Charger Sizing Calculator
AUSELECTRICAL.TOOLS — RENEWABLE & ELECTRIFICATION

EV Charger Sizing Calculator

Charger Current · Combined Load · Voltage Drop

Calculate the current draw for EV charger installations, the combined load when installing multiple chargers, and how this affects total installation maximum demand. This calculator also performs a voltage drop check for the charger circuit and flags where dynamic load management (DLM) may help avoid costly supply upgrades for multi-charger installations.

CALCULATOR

EV Charger Sizing

Common: 7.4kW (32A 1Ø @ 230V), 11kW (16A 3Ø), 22kW (32A 3Ø)
EXISTING INSTALLATION
CABLE CHECK (OPTIONAL)
SINGLE CHARGER CURRENT
31.3
Amps
COMBINED LOAD CURRENT
31.3
Amps
COMBINED CHARGING LOAD
7.2 kW
Voltage drop: 4.4V (1.91%)

Results for guidance only. Verify against current standards and manufacturer data.
Not a substitute for engineering judgement or a licensed professional.

Methodology

Single charger current is calculated from rated power and voltage at unity power factor (EV chargers typically present close to unity PF to the supply). Combined load applies a simultaneity factor — the assumed percentage of chargers operating at full power at the same time — since not all chargers in a multi-unit installation typically charge simultaneously at full rate, especially with load management systems.

Assumptions & Limitations

  • Assumes unity power factor at the charger — verify against specific charger datasheet
  • Simultaneity factor is user-specified — without dynamic load management, conservative design assumes 100%
  • Does not account for charger inrush or soft-start current at connection
  • Cable check uses simplified voltage drop methodology — see Voltage Drop Calculator for full options

Related Calculators

AusElectrical.tools
Built with reference to AS/NZS 3000, AS/NZS 3008, AS/NZS 1359
Results for guidance only — not a substitute for engineering judgement
Does not reproduce copyrighted Standards Australia material. Always consult current standards for compliance.