About the EV Charging Time & Cost Planner
Most charging calculators divide the battery size by the charger’s rating and stop there. That answer is wrong in three predictable ways. A Level 2 charger cannot push more than the car’s onboard charger accepts. A circuit may only be loaded to 80% of its breaker for hours at a time. And a DC fast charger slows sharply above about 80%, so the last fifth of the battery can take as long as the rest.
This planner models all three. AC sessions draw the lower of what your circuit allows and what the car accepts, and add the measured Level 1 and Level 2 charging losses. DC sessions follow a generic taper curve scaled to the car’s published peak power. It is the same curve for every car, not any one manufacturer’s, and it has been checked against twelve fast-charging times the manufacturers publish. Home charging is priced at your state’s EIA average residential rate; public charging at the price the network shows you.
Every battery, peak-power, onboard-charger and range figure in the vehicle list links to the manufacturer’s spec sheet or press kit and the EPA’s fueleconomy.gov record. Where a maker publishes no peak power, the list says so and uses an effective figure worked back from the maker’s own charging time.
Minutes and miles for every 10% of the battery on the fast charger you picked. When the next charger is within reach, the slow bands at the top are usually better spent driving.
Copy the off-peak window and both prices from your utility’s rate plan. The planner runs this session minute by minute at your Level 2 (or Level 1) power and prices each minute at the rate in force.
What each common breaker size gets this car. EV charging counts as a continuous load, so the charger is set to 80% of the breaker (the circuit is sized at 125% of the charger’s current). Wire size, the panel’s spare capacity and permits are for a licensed electrician.
How to Use the EV Charging Time & Cost Planner
Pick your car, drag the two sliders to where the battery is now and where you want it, choose the charger and check the price. The hero number is the session time; beside it are the cost, the energy and the miles of EPA range the session adds. The chart shows how charging power changes across the battery and marks your session on it. The table underneath repeats the same session on a household outlet, a Level 2 circuit and three sizes of fast charger, so you can see what an upgrade or a detour to a faster station would save.
Level 1, Level 2 and DC Fast: What Actually Limits the Speed
AC charging (Levels 1 and 2) goes through the car’s own onboard charger, which converts it to DC for the battery. The session runs at the lowest of three limits: the outlet or circuit, the charging station, and the onboard charger. A standard 15-amp outlet allows a continuous 12 amps at 120 volts, 1.44 kW, which adds three to five miles an hour. A 40-amp Level 2 circuit allows 32 amps, 7.7 kW at 240 volts. On 208-volt supplies, common in apartment garages, the same amps give 13% less. DC fast charging bypasses the onboard charger and feeds the battery directly, so there the limit is the station’s rating or the car’s own maximum, whichever is lower. And the car’s maximum falls as the battery fills.
The Generic Fast-Charging Curve, Stated Plainly
Every EV has its own DC charging curve, and makers rarely publish it. This planner uses one generic curve for every car, scaled to the car’s published peak power. The car draws 75% of peak at 0%, full peak from 10% to 20%, then falls in straight lines to 65% of peak at 50%, 40% at 80%, 22% at 90% and 8% at 100%. The station’s rating caps it at every point. The shape was set to sit in the middle of the twelve 10-to-80% (or 20-to-80%) times the manufacturers in our list publish. Against those claims it lands within 10% for the typical car and within 25% for the worst. Cars with flatter curves, such as Kia’s EV9, charge faster than it predicts, and some others charge slower. Treat the DC time as a good planning number, not a promise about your car. For cars whose makers publish a 10-to-80% time but no peak power, the list shows an effective peak worked back from that time through the same curve, and labels it that way.
What a Session Really Costs
At home you pay for the energy that leaves the wall, which is more than what reaches the battery. A published measurement study (Sears et al., Transportation Research Record 2454, 2014) found Level 2 charging 89.4% efficient and Level 1 83.8%. The planner divides by those figures, so a 50 kWh top-up is billed as about 56 kWh at Level 2. Your state’s rate is the latest monthly average residential price from the U.S. Energy Information Administration, taxes and fees included. A time-of-use plan can halve that overnight, which the subscriber schedule models minute by minute. Public fast chargers bill what they deliver, per kWh or in some states per minute. At 40 to 60 cents per kWh, they cost roughly two to three and a half times the typical home rate.
Getting the Most From a Home Circuit
Bigger is not always better. An onboard charger rated 7.2 kW gains nothing from anything above a 40-amp circuit, and one rated 11 or 11.5 kW is fully used by a 60-amp circuit (48 amps continuous). Above that you are paying for copper the car cannot use. For most drivers even a 30- or 40-amp circuit refills a typical day’s driving overnight. The subscriber circuit planner lists every common breaker size against your car’s own limit and shows the hours for this session on each.
What This Planner Does Not Model
Battery temperature (a cold pack can halve fast-charging power until it warms up), stations that deliver less than their nameplate, two cars sharing one cabinet, idle fees, and the slow final few percent of an AC charge. Miles added are the charged share of the car’s EPA combined range. Highway speed, cold weather and a loaded roof rack all shorten that. Battery figures are what each maker publishes, and the list shows whether the maker calls them usable, total or does not say.
Related tools: compare a year of driving costs with the EV vs Gas Cost Calculator, price a long drive state by state, including charging, with the Road Trip Cost Planner, and see the full cost of owning a car with the True Cost of Ownership Calculator. Browse every Auto & Vehicle tool for more.
Electricity: EIA Electric Power Monthly, average residential retail price by state. Vehicle figures: manufacturer spec sheets and press kits (linked per car) and EPA fueleconomy.gov records. AC charging efficiency: Sears et al. 2014. DC time: a generic taper curve, not any manufacturer’s. Estimates for planning, not a guarantee of any session.
Frequently Asked Questions
Why does DC fast charging slow down after 80%?
A lithium-ion cell can only accept high current while its voltage is well below its maximum. As it fills, the car's battery management lowers the current to protect the cells, which is why every fast-charging curve tapers. In the generic curve this planner uses, going from 80% to 100% takes about as long as 10% to 80%. That is why road-trip advice is to charge to about 80% and drive on, unless the next charger is further away than that 80% will reach.
How long does Level 2 charging take?
Divide the energy you need by the power the car actually draws. A Level 2 charger on a 40-amp breaker delivers 32 amps (a continuous load may use 80% of the breaker), which is 7.7 kW at 240 volts. Adding 50 kWh to the battery then takes about seven hours once charging losses of around 10% are included. A 60-amp circuit allows 48 amps and 11.5 kW, but only if the car's onboard charger accepts that much. Many accept 11 kW, and some only 7.2 kW. The planner applies whichever is lower.
How much does it cost to charge an EV at home?
Energy from the wall times your price per kWh. The wall energy is what the battery gains plus the charging losses: a published measurement study found Level 2 charging about 89% efficient and Level 1 about 84%. At the U.S. average residential rate, about 18 cents per kWh in mid-2026, a 50 kWh top-up drawn at Level 2 costs about $10. The planner uses your state's latest monthly average from the U.S. Energy Information Administration, or a rate you type in, which is better if you are on a time-of-use plan.
Why is my real fast-charging time different from the estimate?
Because every car has its own charging curve, and this planner uses one generic curve scaled to each car's published peak power. Against twelve fast-charging times published by the manufacturers, it lands within a few minutes for most cars but can be off by about a quarter for cars with unusually flat or steep curves. A cold battery, a charger shared with another car, or a station that delivers less than its rating also slows real sessions. Precondition the battery on the way to the charger when your car offers it.
Why are Tesla and Rivian not in the vehicle list?
The bundled list only includes figures a manufacturer or the EPA publishes. Tesla and Lucid do not publish battery capacity. Rivian and the Ford F-150 Lightning do not publish a peak DC charging power or a 10-to-80% time the curve can use. Rather than borrow third-party estimates, the planner leaves them out. Choose Custom and enter the battery, peak DC power and onboard-charger figures you trust, and every calculation works the same way.
