EV Charging Cost and Time Calculator
How long an electric car takes to charge, and what it costs.
Good to know. Fast chargers slow down after about 80%. The last 20% can take as long as the first 60.
How it works
In plain words
The energy needed is the battery size times the share you are adding. About 10% is lost as heat when charging at home, so you pay for a little more. Divide by the charger’s power for the time; rapid chargers slow to about half speed above 80%.
The formula
energy = battery × (to − from) paid for = energy ÷ efficiency (≈ 90%) time = paid for ÷ power · cost = paid for × price
Worked example
Going from 20% to 80% of a 60 kWh battery adds 36 kWh. With about 10% lost in charging, that is 40 kWh from the grid: 5 h 24 min on a 7.4 kW wall box, costing 10.00 at 0.25 a kWh.
Sources
- US Department of Energy, Alternative Fuels Data Center: Charging electric vehicles at home Charging levels, power and typical charging times.
Sources checked September 30, 2026. 3 automated tests check its answers on every change.
About the EV charging cost and time calculator
Charging time and cost both come down to how much energy goes into the battery. Take the battery’s usable size and the share you are adding: 20% to 80% of a 60 kWh battery is 36 kWh. The charger’s power, in kilowatts, sets how fast it flows, and your price per kWh sets the cost.
A small part of the energy is lost as heat in the charger and battery, typically around 10% on a home or public AC charger and less on rapid DC chargers. The calculator adds that to what you pay for. The car also limits the speed: many cars accept only 7 or 11 kW on AC, however powerful the charger, and have their own maximum on DC.
Rapid chargers are fastest in the middle of the battery. Above about 80%, the car slows charging to protect the battery, often to half the speed or less, which is why road trips usually charge to 80% and move on. The calculator assumes half speed above 80% on a rapid charger.
Home charging overnight on an off-peak tariff is usually the cheapest way to charge by far; public rapid chargers often cost two to three times as much per kWh. To compare the running cost with a petrol or diesel car, use the EV vs gas calculator.
Questions people ask
How long does it take to charge an electric car?
About 5 to 8 hours for a typical top-up at a 7.4 kW home charger, or 20 to 40 minutes from 10–20% to 80% on a rapid charger.
How much does it cost to charge an electric car at home?
The kWh added, plus about 10% for losses, times your electricity price: 40 kWh at 0.25 is 10.00.
Should I charge my EV to 100%?
Most makers recommend 80–90% for daily use, and 100% only before a long trip. Some battery types (LFP) are fine at 100%.