EV Charger Requirement Calculator

Work out ev charger requirement instantly with clear inputs, formula shown and shareable results.

About EV Charger Requirement Calculator

Charge point provision is set as a percentage of parking spaces, and the electrical consequence is what matters. Connected load is the count times the rated power, but a diversity factor of 0.5-0.7 reflects that not every point draws full power at once, particularly with load management. That diversified figure sizes the supply.

Formulas

Charge points

Count = ceil(total spaces x EV percentage)

Electrical load

Connected kW = count x rated power; design load = connected x diversity factor

Worked example

With the default values below, EV Charger Requirement Calculator returns Charge points required of 50. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total parking spacesminimum 1: 250
Share to be EV enabledaccepts 1–100 %: 20 %
Power per charge pointminimum 0.5 kW: 7.4 kW
Diversity factoraccepts 0.1–1: 0.6

Results

Charge points required: 50
Connected load: 370.0 kW
Diversified design load: 222.0 kW
Energy per overnight charge cycle: 1,776 kWh

Step by step

1Values used
2Charge points
3Electrical load
4Charge points required= 50
5Connected load= 370.0 kW
6Diversified design load= 222.0 kW
7Energy per overnight charge cycle= 1,776 kWh

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Preliminary estimate only. Electrical supply capacity, protection and metering for EV charging must be designed by a qualified electrical engineer to the wiring regulations in force.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Preliminary estimate only. Electrical supply capacity, protection and metering for EV charging must be designed by a qualified electrical engineer to the wiring regulations in force.

Frequently Asked Questions

How is the EV Charger Requirement figure worked out?

Count = ceil(total spaces x EV percentage). Charge point provision is set as a percentage of parking spaces, and the electrical consequence is what matters.

Can load management reduce the supply needed?

Substantially. Dynamic load balancing across a car park can allow twice as many points on the same supply by sharing capacity, at the cost of slower charging at peak times.

What values do I need to enter?

This calculator takes 4 inputs: Total parking spaces, Share to be EV enabled, Power per charge point, Diversity factor. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.