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EV Charging Cost Calculator – Home, Public & Gas Comparison

Estimate EV charging cost from miles driven, charging mix, charger losses, and electricity rates.

How this calculator helps

EV costs depend on more than one charge session. The useful planning number is usually the energy needed for your weekly driving, adjusted for charging losses and split between home, public Level 2, and DC fast charging rates.

Formula: Driving kWh = miles × kWh per 100 miles ÷ 100. Wall kWh = driving kWh ÷ (1 − charging loss). Monthly cost = weighted wall kWh × weighted electricity rate × 4.345.

Assumptions: Home Level 2 charging is modeled with 10% loss, public Level 2 with 12% loss, and DC fast charging with 15% loss. Charging speed is estimated from wall kWh divided by usable charger power.

Worked example: Driving 220 miles per week at 28 kWh per 100 miles uses about 61.6 battery kWh per week. With 70% home charging at $0.16/kWh, 20% public Level 2 at $0.32/kWh, and 10% DC fast charging at $0.48/kWh, charging costs about $68 per month.

  • Driving miles: Weekly mileage is converted into battery energy demand.
  • EV efficiency: Lower kWh per 100 miles means less electricity for the same driving.
  • Charging mix: Public fast charging can raise the monthly cost even when miles stay unchanged.
  • Gas comparison: Optional gas price and MPG inputs show whether the EV still saves money.
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What the result means

Session cost is useful for understanding one charge, but mileage-based cost is better for ownership planning. A driver who charges mostly at home may spend far less than a driver with the same EV who relies on public fast charging for routine miles.

The charging mix table shows how sensitive your budget is to paid public charging. If the EV only saves money in the mostly-home scenario, an apartment, commute, or road-trip pattern may be the deciding factor rather than the vehicle efficiency alone.

Battery kWh, wall kWh, and driving kWh are related but not identical. The car uses battery energy to move; the charger draws extra wall energy because some power is lost as heat, battery conditioning, and conversion overhead.

Related calculators

Gas mileage cost calculator, Cost per mile calculator, and Energy bill estimator help you plan around household and vehicle energy costs.

Frequently asked questions

  • Does this include the cost of a home charger or installation? No. It estimates ongoing electricity cost, charging time, and gas comparison only.
  • Why split home, public Level 2, and DC fast charging? The same EV can have very different monthly costs depending on where it charges. DC fast charging is often convenient but priced much higher than home electricity.
  • Why use kWh per 100 miles instead of battery size? Battery size tells you capacity; kWh per 100 miles tells you how much energy your actual driving needs.
  • How accurate is the charging-time estimate? It is a planning estimate. Real charging slows near high battery percentages and varies with temperature, charger sharing, battery preconditioning, and vehicle limits.

Last updated: 2026-09-22. This is a planning estimate and should be compared against your actual electricity bill and charging history.

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