EV Charging Time Calculator｜Estimate charge time from charger power and battery size
Enter your battery capacity, current and target state of charge, and charger power to see roughly how long charging takes, the energy used, the electricity cost, and the driving range added. The estimate accounts for the slowdown that happens above 80%.
💡 About this tool
The single thing most EV drivers want to know before plugging in is "how long will this take?" Manufacturer figures usually quote a fixed window like "10–80% in about 30 minutes," which doesn't tell you the time from your actual current charge to the level you want right now.
This calculator works from your battery size and charger power, plus your starting and target percentages, to estimate the energy needed (kWh) and the charging time. You can switch the charger from slow AC Level 2 (3–11 kW) up to high-power DC fast charging (20–250 kW), so you can compare charging at home, at work, and at a highway stop side by side. Add your electricity price and efficiency and you also get the cost of that session and the range it adds. It's built for trip planning: deciding where to stop and what percentage to fill before you set off.
🧐 Frequently Asked Questions
Q. Why does the time jump once I pass 80%? A. Lithium-ion packs charge at high current up to a point (the constant-current phase), then switch to holding voltage while the current tapers off (the constant-voltage phase) as they near full. This tool applies a 0.7x factor above 80% to approximate that slowdown.
Q. My result differs from the manufacturer's rated time. A. Rated times assume ideal battery temperature and power delivery. Real sessions vary with ambient and pack temperature, how many cars share the charger, and your vehicle's own intake limit. Treat the result as a planning estimate.
Q. Should I pick AC or DC charging? A. Higher kW fills faster, but everyday charging on a home AC connection overnight is gentler on the battery and usually cheaper. Most drivers reserve DC fast charging for long trips.
Q. When do I use the custom capacity field? A. Use it for any model not in the preset list, or when a trim level has a different pack size, by entering the battery capacity in kWh directly.
📚 Reading the charging curve
The reason carmakers advertise the 10–80% window is that this is the "fast lane" of the charging curve. Below roughly 70–80%, the battery management system accepts near-peak power; past that, it deliberately throttles current to manage heat and to let lower-voltage cells catch up through cell balancing. As a rule of thumb, the last 20% can take about as long as the whole 10–80% stretch, which is why stopping at 80% on a road trip is usually the time-efficient choice rather than waiting for a full pack.