EV Charging Speed Calculator
See how many miles of range a charger adds per hour — the most intuitive way to think about charging speed.
"Miles per hour of charging" — the real-world metric
The most intuitive way to think about charging speed isn’t kilowatts — it’s how many miles of driving range you gain per hour plugged in. That depends on two things: the charger’s power, and how efficient your EV is.
What that looks like in practice
- Level 1 (1.4 kW) × 3.5 mi/kWh = about 5 mph — barely faster than walking, useful as a top-up only.
- Home Level 2 (7.4 kW) × 3.5 = 26 mph — a full overnight refill, easily.
- Fast Level 2 (11 kW) × 3.5 = 39 mph — common at workplaces and newer installs.
- DC fast 50 kW × 3.5 = 175 mph — a real coffee-stop refill.
- DC fast 150 kW × 3.5 = 525 mph — modern road-trip speed.
- DC fast 350 kW × 3.5 = 1,225 mph — only modern 800 V cars actually accept this.
Real-world DC fast charging is slower than the theoretical number because the car’s charging rate tapers as the battery fills, especially above 80%. Treat these as a best-case figure for the early part of a charge.
Frequently asked
What is "miles per hour of charging"?
A more intuitive measure of charging speed than raw kilowatts. It is how many miles of driving range you gain per hour plugged in. Calculated as charger kW × your EV's mi/kWh efficiency.
Why is the calculator's mph sometimes higher than what I actually see on a DC fast charger?
The calculator assumes the charger delivers its rated power continuously. In real driving, DC fast charging tapers significantly above 80% state of charge — and sometimes earlier if the battery is cold or the stall shares power with the next one. Treat the number as a best-case for the early part of a charge.
Why do I get different mph at different chargers with the same car?
Three reasons: the charger's rated power varies (50 vs 150 vs 350 kW); your car has a peak DC fast rate it cannot exceed regardless of the charger; and stall-sharing on some networks (Tesla V2 Superchargers especially) can split power between adjacent stalls.
How much faster is Level 2 vs Level 1?
About 5–10× faster in everyday use. Level 1 adds 3–5 mph; Level 2 (7.4 kW) adds 20–30 mph for a typical EV. Level 2 is the practical home-charging tier — Level 1 only works if your daily driving is under ~50 miles.
Can my car accept any kW the charger offers?
No — every EV has a peak DC fast charging rate (50, 150, 250, 350 kW etc.). The actual rate is the lower of the charger's capability and the car's capability, further limited by temperature and state of charge.