EV Charging Time Calculator
Estimate how long charging an electric car takes, from the battery size, your charger's power and the charge range you want. Handles home AC and rapid DC charging, with the real-world efficiency and taper accounted for.
How to use this calculator
- Enter the battery capacity and the from/to % you want to charge.
- Pick your charger power — home wallboxes are 7–11 kW, public rapids 50 kW+.
- For rapid DC, charging to 80% is fastest; the last 20% takes disproportionately long.
Formula used
Energy needed is the percentage span of the battery. Divide by the effective charging power — AC is ~90% efficient and steady; DC rapid charging is faster but tapers sharply above 80% to protect the battery, so its effective average rate drops for high charge levels.
Example calculation
A 60 kWh battery from 20% to 80% = 36 kWh. On an 11 kW home charger (~90% eff): 36 ÷ 9.9 = ~3 h 38 min.
On a 50 kW rapid charger: about 51 minutes — but pushing on to 100% could take nearly as long again as the rate tapers.
AC, DC and the 80% rule
Charging time splits into two very different worlds. AC charging (home wallbox, public posts up to 22 kW) is steady and predictable, limited by the car's onboard charger — which often caps below the supply's rating, so an 11 kW post may only deliver 7 kW to a car with a 7 kW onboard charger. It's slow but ideal for overnight top-ups where time doesn't matter.
DC rapid charging bypasses the onboard charger to deliver 50–350 kW directly, but with a crucial catch: the rate tapers steeply as the battery fills, to protect the cells. The first 80% charges fast; the last 20% can take as long again, which is why rapid charging is normally stopped at 80% and long trips are planned around 20–80% top-ups rather than full charges. Understanding this taper is the difference between an efficient road trip and a frustrating one.
Why use this calculator?
- Estimate home overnight and rapid en-route charging times.
- See why rapid charging stops at 80% (the taper is built in).
- Plan charging stops and overnight top-ups realistically.
Frequently asked questions
How long does it take to charge an electric car?
It depends on battery size, charger power and charge level. A 60 kWh car from 20–80% takes ~6 hours on a 7 kW home charger, ~1 hour on a 50 kW rapid. Enter your figures above for a specific estimate.
Why does rapid charging slow down near full?
To protect the battery, charging power tapers sharply above about 80%. The last 20% can take as long as the first 80%, which is why rapid charges are usually stopped at 80% and trips are planned around 20–80% top-ups.
Why won't my car charge at the charger's full rated speed?
For AC charging, the car's onboard charger sets the limit — a 7 kW onboard charger only draws 7 kW even from an 11 or 22 kW post. For DC, the battery's state, temperature and the taper all cap the rate. The slower of car and charger always wins.