Vehicle EconomicsEV Charging Time Calculator
How long will it take to charge your EV from a given charger?
Why this comes up
Charger power ratings (kW) don't map directly to a number of hours without doing the math, and a 240V home charger, a public Level 2 charger, and a DC fast charger produce very different real-world charge times for the same battery, sometimes a difference of 20 minutes versus 8 hours for the same amount of energy. Planning a road trip stop, a home-charging routine before a morning commute, or just sanity-checking a public charger's advertised speed all come down to the same question: how long will this actually take.
How we calculated this
Energy needed at the battery is capacity times the percent-of-charge gap, the difference between your starting and target state of charge. Energy drawn from the charger divides that by your charging efficiency, since some energy is lost as heat during the charging process itself. Charge time is that energy divided by charger power, a straightforward division once the effective energy is known.
Worked example, using this page's own defaults: charging a 75 kWh battery from 20% to 80% at 90% efficiency on a 7.4 kW charger draws 50 kWh from the charger and takes about 6.8 hours.
What this means
- Charging speed drops well before 100% on most EVs and DC fast chargers, this is a planning estimate at a constant rate, not a real taper curve, so treat it as a reasonable floor for fast charging and a close estimate for slower home or Level 2 charging.
- A higher-power charger cuts time roughly proportionally at this constant-rate model, real fast chargers taper more as the battery fills, so the time savings from a bigger charger show up mostly in the early, low-state-of-charge portion of a session.
- See EV Home Charging Cost to find out what this specific charge actually costs, not just how long it takes.
Limitations
Real charging curves taper as the battery approaches full, especially on DC fast chargers, this model assumes a constant rate throughout, so times for a full or near-full charge on a fast charger will run longer in practice than this estimate suggests. See Methodology.
Methodology
A direct energy/power calculation; no shared methodology primitive needed. See methodology.