EV Charging Time Calculator
How long does it take to charge an EV? It depends on the battery, the charger, and how full your battery already is. This calculator handles all three, including the realistic tapering curve for DC fast charging.
How to use this calculator
- Battery capacity (kWh). your EV's total battery size. Check the spec sheet. Most modern EVs are 40-100 kWh.
- Charger power (kW). the charger's max output. Level 1 = ~1.4 kW. Level 2 = 3.3-19.2 kW typically. DC fast = 50-350 kW.
- Start SOC and End SOC. the percentage of battery you start with and want to end with. Real-world public charging is usually 20% → 80%.
Why the tapering matters
On DC fast chargers (above ~22 kW), the charging rate doesn't stay constant. It holds at peak power up to roughly 80% state-of-charge, then drops off rapidly. This is a battery-protection behavior every modern EV implements. Charging from 80% to 100% can take as long as charging from 20% to 80%, which is why most road-trip advice tells you to charge to 80% and move on.
What this doesn't account for
- Cold-weather slowdowns. Below freezing, charging is 20-50% slower until the battery warms up.
- Vehicle onboard charger limits. A car with a 7.2 kW onboard charger plugged into an 11 kW Level 2 station will only draw 7.2 kW. Use the onboard charger spec, not the station spec, for AC charging.
- Charging session overhead. Authentication, plug handshake, and ramp-up take 1-3 minutes in addition to the actual charging.
- Network throttling. Some stations share power between bays. The advertised kW may not be what you actually get.