Calculator
EV Charging Time Calculator
How long will it take to charge your EV? Enter your battery size and charger speed to get the answer — for any charger level from a standard 120V outlet to a 250 kW Supercharger.
Time to charge
0h 0m
How charging time is calculated
The formula divides the energy you need by how fast the charger delivers it, with a small adjustment for charging losses:
kWh needed = (target % − current %) / 100 × battery size
Hours = kWh needed / charger kW / 0.9
Example: charging a 75 kWh battery from 20% to 80% (45 kWh) on a 7.2 kW Level 2 home charger takes 7.0 hours. The same charge on a 150 kW Supercharger takes about 20 minutes — though real-world times above 50% will be longer because the charging curve tapers.
Frequently asked questions
How long does it take to fully charge an EV?
On a Level 2 home charger (7.2 kW), a typical 75 kWh EV charges from 0 to 100% in about 11.5 hours. At a DC fast charger (150 kW), the same charge takes around 35 minutes — but only up to 80%, since fast charging slows significantly above 80% to protect the battery.
Why does fast charging slow down above 80%?
Above 80% state of charge, the battery management system tapers the charging rate to protect lithium-ion cells from heat damage and dendrite formation. A 250 kW charger might be delivering only 60–80 kW by 90%. For road trips, charging to 80% and moving on is usually faster than waiting for a full charge.
Is the calculator accurate for real-world charging?
The calculator assumes a constant charging rate, which is accurate for Level 1 and Level 2 charging (rates are stable). For DC fast charging, real times are typically 10–30% longer than calculated because the charging curve tapers — particularly above 50% state of charge. Add 15% buffer for fast-charge estimates.
What about cold weather charging times?
Cold batteries charge more slowly. Below 32°F, expect 20–40% slower charging on DC fast chargers because battery preconditioning takes time. Most modern EVs (Tesla, Rivian, Ford) precondition the battery automatically when you navigate to a fast charger.