Estimate EV charging time from battery size, charge levels and charger power (Level 1/2 or DC fast), plus energy and range added.
Estimate only — DC fast charging tapers above ~80%, and cold batteries or shared stalls make real charging slower than shown.
About this tool
EV Charging Time Calculator is a free, in-browser tool that estimates how long it takes to charge an electric vehicle from one state of charge to another. Enter the usable battery capacity in kilowatt-hours, the current and target charge percentages, and pick a charger — Level 1 (1.4 kW), Level 2 (7.7, 11 or 19.2 kW), DC fast (50, 150 or 250 kW) or a custom power. Everything is computed locally in your browser.
The energy the battery needs is capacity × (target − current) ÷ 100 kilowatt-hours. Because some grid energy is lost as heat, the time is that energy divided by the charger power multiplied by a charging efficiency (default 0.9): time = energy ÷ (power × efficiency). If you enter your car's efficiency in miles per kWh, the tool also shows the driving range added.
This is an estimate. On a DC fast charger the real time is longer than the simple calculation because the charging rate tapers sharply above roughly 80% to protect the battery, and cold batteries, a nearly full pack and power sharing between stalls all slow things further. For fast charging, stopping at 80% is usually the most time-efficient choice.
Frequently asked questions
Why is real DC fast charging slower than this estimate?
Fast chargers ramp their power down as the battery fills — the taper usually starts well before 80% and steepens after it — so a flat power assumption underestimates the time for high target percentages. This tool models average power and does not simulate the taper.
What is the efficiency factor for?
Not all energy drawn from the charger ends up in the battery; some is lost as heat in the cables, charger and battery. The efficiency (around 0.85–0.95, default 0.9) accounts for that loss, so the estimated time is a little longer than energy ÷ power alone.
How is range added calculated?
If you enter your car's efficiency in miles per kWh, range added is the energy put into the battery multiplied by that figure. Real range depends on speed, terrain, climate control and temperature, so treat it as an estimate.
Which charger power should I pick?
Level 1 is a standard household outlet (about 1.4 kW), Level 2 is a 240 V home or public charger (7.7–19.2 kW), and DC fast chargers run 50–250 kW or more. Use Custom to enter the exact rated power of your charger. All math runs in your browser.