EV vs Petrol Running-Cost Calculator: South Africa

Put both cars on the same monthly distance

Enter the distance you expect to drive, not the distance needed to make one car look economical. Use petrol consumption in litres per 100 km and EV consumption in electricity bought at the wall per 100 km. The public-charging share is a share of electricity purchased, not a count of charging sessions.

Energy only. Excludes charging-session fees, parking, subscriptions, charger installation, vehicle price, finance, insurance, maintenance and resale. Add any applicable fixed charging costs separately.

The dashboard and the meter may tell different stories

Electricity used by the vehicle and electricity purchased to charge it are not necessarily equal. Some energy is lost during charging. The calculator therefore asks for wall consumption: if your figure already comes from billed electricity, it includes that loss and must not be inflated again.

For an actual ownership comparison, record electricity bought and distance driven over a representative period. Use similar starting and ending battery levels, or account for the change in stored energy. A week that finishes with a much lower battery is not a fair measure of the electricity needed to repeat that week.

Use the same discipline with petrol. A credible fuel-use input comes from repeatable use or the exact applicable test, not the best reading briefly seen on a dashboard. If comparing official consumption figures, check their measurement basis and do not claim the result is a measured real-world saving.

Energy-boundary background: the US Department of Energy's explanation of wall-to-battery losses. Its historical example is not a universal charging-loss percentage; this calculator does not impose it on a South African vehicle.

Cheap home charging does not describe a public-only owner

Try three versions of your scenario: the charging mix you expect, a month with more public charging, and public-only use. Keep the car's consumption and distance unchanged so you can see what the tariff does to the result. Do not use an AC price for sessions that would actually be billed on a different tariff.

The default arithmetic is deliberately ordinary: 1,500 km a month, a hypothetical petrol car using 7 L/100 km at R22/litre, and an EV buying 18 kWh/100 km at R3/kWh with no public charging. It produces R2,310 for petrol and R810 for electricity. Those inputs are teaching numbers—not today's national fuel price, a municipal tariff or ratings for named cars.

Change the public share to 100% at the illustrative R7/kWh and the same EV's monthly electricity becomes R1,890. The vehicle has not changed; the way its energy is bought has. This is why an EV recommendation should not promise a home-tariff saving to someone who parks on the street.

A monthly household connection fee is not automatically an incremental EV expense if you already pay it unchanged. An upgrade required specifically for charging may be. Compare the additional costs actually caused by the vehicle and avoid counting the same bill twice.

A saving per kilometre is the beginning of the decision

Suppose one car costs more to buy but less to energise. The time it takes to recover the price difference depends on distance and the saving—not on the fact that it has an electric badge. Insurance, finance and the charger quotation can move that result, while resale remains a scenario rather than a promise.

Use this tool to establish a transparent energy subtotal, then carry it into the whole-ownership-cost guide. Do not add the financed principal and the purchase price as separate costs for the same car. When testing affordability, distinguish a monthly cash budget from the economic cost of depreciation.

A PHEV needs a different comparison because it buys two forms of energy. Do not enter a battery-assisted petrol figure here and omit its electricity. The PHEV charging-routine guide explains how to avoid that shortcut.