This estimator shows how a tire-related efficiency penalty can increase the energy that an EV must replace and, in turn, the time spent charging. It is useful when comparing tire sizes, pressures, compounds, or seasonal setups.
The calculation separates baseline session energy from additional energy caused by the entered tire penalty. Real charging time can still vary with battery temperature, charge curve, station sharing, and taper near a high state of charge.
1. Enter trip distance
Use the miles driven before the charging stop.
2. Add baseline efficiency
Enter the vehicle efficiency on the reference tire setup.
3. Set the tire penalty
Use the estimated percentage reduction in miles per kWh from the alternate tires or pressure condition.
4. Enter delivered charger power
Use average power for the session, not only the charger nameplate rating.
5. Review total and added time
Compare the modeled session with the baseline time shown in the breakdown.
The tire penalty and charging loss are converted from percentages to decimals. Power is in kilowatts, so time is initially calculated in hours and then converted to minutes.
The headline is the estimated charging time required to replace energy used over the entered distance with the selected tire penalty.
This is an energy-replacement estimate and does not model the vehicle-specific charging curve or a target state-of-charge window.
Given: 180 miles, 3.5 mi/kWh baseline efficiency, 6% tire penalty, 90 kW average power, and 10% charging loss.
Calculation: Baseline battery energy = 180 / 3.5 = 51.43 kWh. Adjusted battery energy = 51.43 / 0.94 = 54.71 kWh. Grid energy = 54.71 / 0.90 = 60.79 kWh. Time = 60.79 / 90 = 0.675 hours.
Result: About 41 minutes, roughly 2.4 minutes longer than the baseline session.
Wider tires, aggressive tread, low pressure, heavier wheels, and winter compounds can increase rolling resistance or aerodynamic drag.
Usually not. Enter the average delivered power across the session because charging often tapers as the battery fills.
This page accepts zero or a positive penalty. For an efficiency improvement, compare two runs by entering the more efficient setup as the baseline.
Some energy is lost in cables, power electronics, battery conditioning, and heat, so grid energy can exceed energy stored in the battery.
No. It estimates the time to replace energy used over the specified distance.