EV Charger Level Comparison Calculator
Compare Level 1, Level 2, and DC Fast Charge times and costs for your electric vehicle based on battery capacity, current charge level, and local electricity rates.
Total usable battery capacity of your EV (e.g. 75 kWh for Tesla Model 3 Long Range)
Your battery's current charge level (0–99%)
Desired charge level (1–100%). DC Fast Charge typically limited to 80%.
Your local electricity cost per kWh (US average ≈ $0.13/kWh)
Energy delivery efficiency (Level 1 ≈ 85%, Level 2 ≈ 90%, DCFC ≈ 92%)
Formulas Used
1. Energy needed (kWh delivered to battery):
E_battery = Battery_Capacity × (Target_SOC% − Current_SOC%) / 100
2. Grid energy drawn (kWh from wall):
E_grid = E_battery / Charger_Efficiency
3. Charging time (hours):
Time = E_grid / Charger_Power_kW
4. Total electricity cost:
Cost = E_grid × Electricity_Rate ($/kWh)
5. Estimated miles of range added:
Miles = E_battery × 3.5 miles/kWh (EPA average efficiency)
6. Cost per mile:
Cost_per_mile = Total_Cost / Miles_Added
Assumptions & References
- Level 1: 120V AC, 12A circuit → 1.44 kW (rounded to 1.4 kW); standard 3-prong household outlet (NEMA 5-15). Source: SAE J1772.
- Level 2: 240V AC, 30A circuit → 7.2 kW; requires dedicated EVSE (NEMA 14-50 or hardwired). Source: SAE J1772.
- DC Fast Charge (DCFC): 480V DC, ~50 kW (standard CCS/CHAdeMO); modern chargers can reach 150–350 kW. Source: CHAdeMO Association, SAE J1772 Combo.
- Charger efficiency: Level 1 ≈ 85%, Level 2 ≈ 90%, DCFC ≈ 92%. User input is used as a baseline and scaled per charger type. Source: EPRI, DOE AFDC.
- Average EV efficiency: 3.5 miles/kWh used for range estimates (EPA average across popular EVs, 2023). Actual efficiency varies by vehicle, speed, and temperature.
- US average electricity rate: ~$0.13/kWh (EIA, 2023). Public DCFC stations typically charge $0.25–$0.60/kWh or per-minute fees.
- DC Fast Charge SOC limit: Charging above 80% SOC on DCFC significantly slows due to battery management system (BMS) taper — plan accordingly.
- Cost estimates reflect home electricity rates only. Public charging station fees, network fees, and idle fees are not included.
- References: U.S. DOE Alternative Fuels Data Center (afdc.energy.gov), SAE International J1772, EPA fueleconomy.gov, EIA Electric Power Monthly.