How to use this calculator
Replace the example values with your own measurements or specifications. Keep the units shown beside each label. Results update as you type; reset restores the example.
Use average power, not a charger’s advertised peak. The vehicle, electrical supply, temperature, and charging taper can limit power. This simple constant-average-power model is not a vehicle-specific DC charging curve.
The formula
A worked example
Adding 45 kWh with 7.2 kW average wall power at 90% efficiency takes about 6.94 hours, or 6 hours 57 minutes.
Common questions
Why can fast charging take longer than this result?
Power often declines as the battery fills. If you enter peak power instead of actual average power, the estimate will be too short.
Does a larger charger always help?
Only when the vehicle and electrical connection can accept the additional power.
Sources & calculation method
Related guidance: U.S. Department of Energy: EV charging. Accessed September 9, 2026. The equation above describes this tool’s model; the reference provides practical context and does not endorse this site.
Prepared with AI assistance. Formula examples and input validation have automated checks. This page has not received an independent automotive professional review. Read our review standards.