EV Charging Cost Calculator

Q: How much does it cost to charge an electric car?

Cost = battery kWh × (SoC_to - SoC_from)/100 ÷ charging_efficiency × rate. For a 75 kWh battery from 20% to 80% at 90% efficiency and $0.15/kWh: 75 × 0.6 ÷ 0.9 × 0.15 = $7.50.

Q: Is it cheaper to charge at home or a public charger?

Home charging is almost always cheaper. Home rates average $0.13–$0.17/kWh. Public DC fast chargers typically cost $0.30–$0.60/kWh. Some networks charge per minute, which can be even more expensive if the car charges slowly. Off-peak home charging is the cheapest option.

Q: What is charging efficiency and why does it matter?

Charging efficiency (typically 85–95%) is the ratio of energy stored in the battery to energy drawn from the grid. Some energy is lost as heat in the charger and cables. A 7.2kW Level 2 charger at 90% efficiency puts 6.48 kW into the battery. This affects both time to charge and total cost.

Find out exactly how much it costs to charge your electric vehicle. Enter your battery size, current and target state of charge, charging efficiency, and electricity rate.

Calculate EV Charging Cost

Battery Capacity (kWh)Find on vehicle spec sheet or owner's manual

Current SoC (%)

Target SoC (%)

Charging Efficiency (%)Level 2 AC: ~90–95%. DC fast: ~85–92%

Charger Power (kW)Level 1: 1.4kW, Level 2: 7.2–22kW, DC: 50–350kW

Currency

Rate per kWh

Charging Session Result

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Energy Added (kWh)

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Grid Draw (kWh)

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Charging Cost

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Approx. Charge Time (hrs)

Formula

Energy added to battery (kWh) = Battery capacity × (SoC_to − SoC_from) ÷ 100
Grid draw (kWh) = Energy added ÷ (Efficiency ÷ 100)
Cost = Grid draw × Rate
Charge time (hrs) = Energy added ÷ Charger power

Common EV Battery Sizes

Vehicle	Battery (kWh)	Range (approx.)
Nissan Leaf (standard)	40	240 km / 150 mi
Nissan Leaf (Plus)	62	385 km / 240 mi
Tesla Model 3 (Standard)	57.5	430 km / 270 mi
Tesla Model 3 (Long Range)	82	615 km / 385 mi
Tesla Model Y (Long Range)	82	595 km / 370 mi
VW ID.4 (77 kWh)	77	520 km / 323 mi
Hyundai Ioniq 6 (long)	77.4	610 km / 379 mi
Chevrolet Bolt EV	65	415 km / 259 mi

Charging Levels Explained

Level 1 (120V AC, ~1.4 kW): Standard US household outlet. Adds 8–15 km per hour. Fine for short daily drives, impractical for larger batteries.
Level 2 (240V AC, 7–22 kW): Dedicated home or commercial charger. Adds 30–130 km per hour. Most common for overnight home charging.
DC Fast Charging (50–350 kW): Public fast chargers (CCS, CHAdeMO, Tesla Supercharger). 80% charge in 20–60 minutes. Cost $0.30–$0.60/kWh at public stations.

Frequently Asked Questions

How much does it cost to charge an electric car?

For a 75 kWh battery from 20% to 80% (adding 45 kWh) at 92% efficiency: 45 ÷ 0.92 = 48.9 kWh drawn. At $0.15/kWh that's $7.33. A full charge from 0% costs about 90 kWh drawn × rate. Home overnight charging is typically $8–$15 for most EVs at US average rates.

Is it cheaper to charge at home or a public charger?

Home charging is typically 50–70% cheaper than public fast charging. Home rates: $0.10–$0.20/kWh. Public DC fast chargers: $0.30–$0.60/kWh. If you have off-peak rates (some utilities offer EV plans with overnight rates as low as $0.07/kWh), home charging becomes even cheaper. Public charging is convenient for long trips but shouldn't be your primary charging strategy.

What is charging efficiency and why does it matter?

Charging efficiency (typically 90–95% for Level 2 AC) is the ratio of battery energy stored to grid energy consumed. The rest is lost as heat in the onboard charger and cables. If efficiency is 90%, charging 60 kWh into the battery draws 60 ÷ 0.9 = 66.7 kWh from the grid. In cold weather, efficiency can drop below 80% as the battery heater draws power.