Charging Time Calculator by EV Model and Charger Level
Estimate how long it will take to charge your electric vehicle based on the EV model, current battery level, target battery level, and charger type.
Typical onboard charger efficiency is 85–95%. DC fast charging is typically 90–95%.
Formula
Energy Needed (kWh) = Battery Capacity (kWh) × (Target SOC% − Current SOC%) / 100
Energy from Grid (kWh) = Energy Needed / (Charging Efficiency / 100)
Charging Time (hours) = Energy from Grid / Charger Power (kW)
Example: A 77 kWh EV charging from 20% to 80% on a 7.2 kW Level 2 charger at 90% efficiency:
Energy Needed = 77 × 0.60 = 46.2 kWh | Energy from Grid = 46.2 / 0.90 = 51.33 kWh | Time = 51.33 / 7.2 ≈ 7.13 hours (~7 hr 8 min)
Assumptions & References
- Battery capacities listed are usable (net) capacity figures commonly cited by manufacturers.
- Level 1 charging assumes a standard 120V / 12A circuit delivering approximately 1.4 kW.
- Level 2 charging assumes a 240V circuit; actual power depends on the vehicle's onboard charger limit (typically 7.2–19.2 kW).
- DC Fast Charging bypasses the onboard charger; actual rate depends on the vehicle's DC charge acceptance rate and battery state.
- Charging efficiency (85–95%) accounts for heat losses in the onboard charger and battery management system (SAE J1772).
- Cost estimate uses the U.S. average residential electricity rate of $0.16/kWh (U.S. EIA, 2024).
- Miles-added estimate uses an average EV efficiency of 3.5 miles/kWh (U.S. DOE average across popular EV models).
- Charging speed may taper (slow down) above ~80% SOC for battery longevity; this calculator assumes a constant charge rate.
- References: U.S. Department of Energy – Alternative Fuels Data Center; SAE International J1772 Standard; U.S. EIA Electric Power Monthly.