byGrace Buchan/9 June 2026/inHelp & Advice, Kia News

How Much Does It Cost to Charge an EV? Here’s How to Work It Out

One of the most common questions we hear at Miles Kia is: “How much will it cost to charge an electric vehicle?”

The answer is actually quite simple. Once you know your vehicle’s energy consumption and your electricity rate, you can calculate charging costs in just a few seconds.

Whether you’re considering a Kia EV3, EV5 or EV9, here’s an easy way to understand the numbers.

The Three Numbers You Need

Before doing any calculations, find these figures:

1. Energy Consumption

Measured in kWh/100km, this tells you how much electricity the vehicle uses to travel 100 kilometres. Think of it as the EV equivalent of fuel economy.

2. Battery Capacity

Measured in kWh, this tells you how much energy the battery can store.

Think of it as the EV equivalent of a fuel tank. The larger the battery capacity, the more electricity is required for a full charge, but generally the further you can travel between charges.

3. Electricity Price

Measured in cents per kWh, this is what your electricity provider charges you for power. Your rate will depend on your provider and whether you’re charging during peak or off-peak hours.

Formula 1: Cost to Drive 100km

Use this formula:

Cost per 100km = (Energy Consumption × Electricity Price) + RUCs

This tells you your everyday running cost.

Formula 2: Cost of a Full Charge

Use this formula:

Full Charge Cost = Battery Capacity × Electricity Price

This tells you approximately how much it costs to charge from 0% to 100%.

Example: Kia EV3 Light SR

Let’s put the maths into practice using the Kia EV3 Light SR.

Specification	Figure
Battery Capacity	58.3 kWh
Energy Consumption	14.9 kWh/100km

Scenario 1: Charging at Home on an Off-Peak EV Plan

Many electricity providers offer discounted overnight EV rates.

Electricity rate: $0.13/kWh*

Cost Per 100km
14.9 × $0.13 = $1.94
+ RUCs $7.60
= $9.54 per 100km

Full Charge Cost
58.3 × $0.13 = $7.58

Result
$9.54 per 100km (incl RUCs)
$7.58 for a full charge

Scenario 2: Standard Home Electricity Rates

If you’re charging during the day on a standard household plan:

Electricity rate: $0.30/kWh*

Cost Per 100km
14.9 × $0.30 = $4.47 per 100km
+ RUCs $7.60
= $12.52 per 100km

Full Charge Cost
58.3 × $0.30 = $17.49

Result
$12.07 per 100km (incl RUCs)
$17.49 for a full charge

Scenario 3: Public DC Fast Charging

Public fast chargers are ideal for road trips and long-distance travel, but they generally cost more.

Electricity rate: $0.80/kWh*

Cost Per 100km
14.9 × $0.80 = $11.92
+ RUCs $7.60
= $19.52 per 100km

Full Charge Cost
58.3 × $0.80 = $46.64

Result
$19.52 per 100km (incl RUCs)
$46.64 for a full charge

While EV charging costs might seem complicated at first, the maths is actually quite straightforward once you know what to look for. By understanding your vehicle’s energy consumption, battery size and electricity rate, you can quickly work out both your charging costs and day-to-day running costs.

For most New Zealand drivers, charging at home will deliver the greatest savings, particularly when taking advantage of off-peak electricity rates.

Whether you’re considering your first electric vehicle or comparing models, knowing how to calculate charging costs can help you make a more informed decision. If you’d like to learn more about Kia’s growing electric vehicle range, the team at Miles Kia is always happy to help.

*Pricing disclaimer: All cost calculations, electricity plan rates, and government RUC figures are estimates based on market rates and are subject to change.