Plan smarter charging and cut electricity costs quickly. Model peak windows and real driving habits. Switch schedules, compare plans, and track savings every month.
| Daily miles | Days | kWh/mi | Loss % | On % | Off % | Flat rate | On rate | Shoulder rate | Off rate | Monthly savings |
|---|---|---|---|---|---|---|---|---|---|---|
| 32 | 22 | 0.3 | 10 | 20 | 70 | 0.20 | 0.32 | 0.24 | 0.16 | $0.00 |
Time-of-use pricing changes the unit economics of EV charging by tying cost to the hour you draw energy. If a flat rate is 0.22 per kWh and off-peak is 0.16, shifting 150 kWh monthly saves about 9.00 before fees. This calculator converts your miles into billed kWh, then prices each share at on-peak, shoulder, and off-peak rates. It highlights whether timing changes outweigh added fees and real-world efficiency differences today.
Charging losses meaningfully move the bill because utilities measure energy at the meter, not at the battery. With a 10% loss, the meter supplies 111 kWh to deliver 100 kWh stored. At 0.32 on-peak pricing, that extra 11 kWh costs 3.52, while the same loss at 0.16 off-peak costs 1.76. Accurate loss inputs sharpen plan comparisons.
Driving intensity sets the savings ceiling. A commuter driving 30 miles daily for 22 days logs 660 miles monthly. At 0.30 kWh per mile, wheels energy is 198 kWh, and billed energy is about 220 kWh with 10% loss. Every 0.05 difference between effective rates is then worth roughly 11.00 per month. Higher mileage increases both risk on peak windows and upside from shifting schedules.
Rate spreads matter more than perfect forecasting. When on-peak is 0.34, shoulder is 0.24, and off-peak is 0.16, the spread from peak to off-peak is 0.18. Moving charging from peak to off-peak by 60% on a 220 kWh month can change costs by about 23.76. The calculator auto-fills shoulder as the remaining share so the split always totals 100%.
Plan fees and taxes can erase small gains. Some time-based plans add 8 to 20 monthly fees, and taxes may apply to energy charges. If energy savings is 12.00 but the plan fee is 15.00, net savings becomes -3.00. Use the cost graph to test conservative and optimistic splits, then confirm with your bill’s effective rate, seasonal calendars, and charging app history.
Charging loss accounts for heat, power conversion, and battery conditioning. It increases the energy drawn from the meter, which directly increases costs under both pricing plans.
Set the shoulder rate equal to either peak or off-peak, then use the split fields. The remaining share will still balance to 100%.
Use your charging app history. Count kWh charged during peak hours divided by total monthly kWh. Enter that value as on-peak share, then set off-peak share accordingly.
No. This model focuses on home electricity pricing. If you pay per kWh at public chargers, add that cost separately to your monthly transportation budget.
If most charging occurs on-peak, or if plan fees exceed energy savings, the time-based option can cost more. Negative savings indicates an estimated increase.
Accuracy depends on your real kWh per mile, losses, and charging times. Use one month of actual miles and charging data to calibrate inputs, then re-run for better estimates.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.