EV charging, solved.
Four quick calculators for the questions every EV owner actually asks: how long it takes, what it costs, how far it goes, and whether your house can handle it.
How long to charge?
Estimate the time to charge from your current level to your target, on any charger from a wall outlet to DC fast.
Assumptions & sources
Energy = battery × (target − start). AC charging assumes ~90% onboard efficiency; DC fast charging slows sharply past 80% (a taper penalty is applied). Range added uses ~3.5 mi/kWh. Based on EPA efficiency norms and typical onboard-charger specs.
What will it cost — vs gas?
Compare the monthly cost of charging at home against the same miles in a gas car.
Assumptions & sources
EV energy includes ~10% charging loss (kWh = miles ÷ efficiency ÷ 0.9). Gas cost = miles ÷ MPG × price. The sparkline shows cumulative savings over five years. Default rate ≈ U.S. residential average (EIA); adjust to your utility or time-of-use plan.
Will my panel handle it?
A quick check of whether a Level 2 charger fits within your panel's safe capacity, using the 80% continuous-load rule.
Assumptions & sources
Continuous loads count at 125% (NEC), so a 40A charger needs a 50A breaker and counts as 50A. Usable capacity is 80% of the main rating. "Fits" means existing load + charger stay under that 80% line. A simplified planning estimate — verify with a licensed electrician.
How far on a full charge?
Estimate real-world range from your battery size and efficiency, including a cold-weather hit.
Assumptions & sources
Full range = battery × efficiency. Usable assumes ~90% (you rarely run to 0%). Cold weather applies a 30% reduction, typical for heating and battery losses in winter. Real range varies with speed, terrain and climate.
EV charging questions, answered
Direct answers to the things people ask most before buying an EV.
How long does it take to charge an EV at home?
A typical 60 kWh EV charging from 20% to 80% takes about 5 hours on a 9.6 kW Level 2 charger. Level 1 (a standard outlet) is far slower at roughly 24 hours for the same amount, while DC fast charging can do it in under an hour.
How much does it cost to charge an EV?
At the U.S. average of about 17 cents per kWh, charging an EV that travels 3.5 miles per kWh costs roughly 5 cents per mile. Driving 1,000 miles a month works out to around $49, usually well under half the cost of gasoline.
Do I need to upgrade my panel for an EV charger?
Not always. A 40-amp Level 2 charger needs a 50-amp breaker and draws 9.6 kW continuously. If your panel and existing loads leave that much headroom within the 80% rule, you are fine. If not, a load-management device often avoids a full upgrade.
What is the difference between Level 1 and Level 2 charging?
Level 1 uses a standard 120-volt outlet and adds about 3 to 5 miles of range per hour. Level 2 uses a 240-volt circuit and adds roughly 20 to 35 miles per hour, making it the practical choice for charging fully overnight at home.
Is it cheaper to charge at home or at a public station?
Home charging is almost always cheaper. Residential electricity averages around 17 cents per kWh, while public DC fast charging often costs 40 to 60 cents per kWh. Charging overnight at home can cut your per-mile cost by more than half versus fast charging on the road.