What Does It Cost to Charge an EV at Home?
Begin with energy, not the size of the plug
The basic cost of charging an electric vehicle depends on how much energy you add and the price of that electricity. Charger power affects charging time, but a faster charger does not automatically make every kilowatt-hour cheaper. Your tariff, vehicle limits and charging losses also matter.
Carvago’s EV Charging Cost Calculator uses a usable battery capacity, a starting and target state of charge, electricity price, charging efficiency and effective charger power. It is a simplified planning model, not a vehicle diagnostic or a live tariff service.
Estimate the energy going into the battery
Battery energy added = usable battery capacity × (target percentage − starting percentage) ÷ 100. For an illustrative 60 kWh usable battery charged from 20% to 80%, the increase is 36 kWh. Use usable capacity where available; the gross battery capacity may include an inaccessible reserve.
The target must be higher than the starting percentage for a charging session. Follow the vehicle manufacturer’s guidance about routine charge limits, storage and battery care rather than treating an example percentage as a recommendation.
Account for charging efficiency
Not all electricity drawn from the supply becomes stored battery energy. The model defines charging efficiency as battery energy added divided by energy drawn from the wall. With 90% efficiency, 36 kWh added requires an estimated 40 kWh from the supply: 36 ÷ 0.90.
Multiply the supply energy by your tariff. At an illustrative price of 0.20 per kWh, the session cost is 8.00 in the selected currency. This is an example calculation, not a current electricity rate. The currency selector does not convert prices.
Understand the time estimate
Ideal time = supply energy ÷ effective charger input power. If the estimated wall energy is 40 kWh and the effective input power is 7 kW, ideal duration is about 5.71 hours. Use the lower effective limit of the charger, vehicle and electrical supply, not simply a marketing maximum.
Actual charging power can vary or taper. Battery temperature, state of charge, thermal management and household load sharing may change the session. The calculator assumes constant effective input power and does not model charging curves.
Check the tariff beyond the headline unit price
A time-of-use plan may have different prices overnight and during peak hours. If charging spans more than one price period, calculate the portions separately or use a carefully chosen blended rate. Do not assume the cheapest overnight rate applies to the entire session.
Standing charges, charger installation, equipment costs, parking, public-network session fees and subscriptions are not included in the simple energy result. Include them separately when comparing home and public charging.
Plan safely and compare like for like
Have charging equipment assessed and installed by a suitably qualified professional under the applicable local rules. A cost calculator cannot assess a circuit, cable, socket, earthing arrangement or electrical safety. Never use an energy estimate as permission to exceed equipment ratings.
- Confirm usable battery capacity.
- Enter a target above the starting state of charge.
- Use your real tariff and one currency.
- Include charging losses through the efficiency input.
- Treat time as an ideal estimate, not a guarantee.
With those boundaries clear, you can compare charging scenarios without confusing a neat number with a promise about your next session.