EV charging time calculator
Estimate how long an EV charge will take, from your battery size, the charge range and your charger's power output.
Result
Charging time
How to use this calculator
- Enter your battery capacity and the charge-from/charge-to percentages.
- Enter your charger's power rating (7kW home wallbox, 50kW+ rapid, 150kW+ ultra-rapid).
- Read the estimated charging time.
Assumptions
- Assumes a constant charge rate for the whole session — real rapid/ultra-rapid charging slows significantly above ~80%, so this underestimates time for high charge-to percentages on DC fast chargers.
- Uses whichever of charger power or car's max charge rate you enter — enter the lower of the two for an accurate result.
Technical details: what the fields mean
- Battery capacity
batteryCapacityKwh - Your EV's usable battery capacity, in kWh.
- Charge from
chargeFromPercent - Battery level before charging starts.
- Charge to
chargeToPercent - Battery level you're charging up to.
- Charger power
chargerPowerKw - The charger's rated power output — not your car's maximum charge rate, whichever is lower actually applies.
- Charging efficiency
chargingEfficiencyPercent - Accounts for energy lost as heat during charging; 90% is a reasonable typical estimate.
Methodology
Time = (capacity × (to% − from%) ÷ 100) ÷ (charger power × efficiency).
Worked example
60kWh battery, 20% → 80%, 7kW home charger
Inputs: batteryCapacityKwh=60, chargeFromPercent=20, chargeToPercent=80, chargerPowerKw=7
Result: 5.7 hours
Practical guidance
- For a home overnight charge, a 7kW wallbox easily covers a typical daily top-up.
- For rapid/ultra-rapid charging, expect the real charging curve to taper off above 80% — many drivers stop around 80% on a road trip for this reason.
Common mistakes
- Entering the charger's maximum power when your car actually charges slower — use the lower of the two figures.
- Assuming a constant charge rate all the way to 100% on a rapid charger, which is unrealistic.
FAQs
How long does it take to charge an EV from 20% to 80% at home?
For a 60kWh battery on a 7kW home charger, about 5.7 hours.
Why does rapid charging slow down near 100%?
Battery management systems reduce charge rate as the battery fills to protect battery health — this model assumes a constant rate, so treat times above ~80% on DC rapid chargers as optimistic.