There is no standard off-peak discount, which is why no honest article can quote you one. The saving is a subtraction you can do yourself: your peak rate minus your off-peak rate, multiplied by the charging energy you actually move into the cheap window. At the labelled example rates in the table below — 30 cents peak, 10 cents off-peak — shifting 300 kWh of charging a month saves $60 against charging at peak, or about $25 against the U.S. average residential price of 18.31 cents per kWh. Your two rates, from your own tariff, decide your figure.
Key Takeaways
- There is no standard off-peak discount — the saving is your rate gap times the energy you actually shift.
- You need three numbers: your peak rate, your off-peak rate, and your monthly charging kWh.
- At example rates of 30¢ peak and 10¢ off-peak, shifting 300 kWh a month saves $60 against peak charging.
- Whole-house repricing and fixed charges shrink the headline figure — schedule the session start inside the window.
The Only Three Numbers You Need
- Your peak rate, in cents per kWh, from the tariff or rate sheet for your plan — the same document that lists the off-peak window.
- Your off-peak rate, from the same sheet. The gap between the two, not either number alone, is what a shifted session earns.
- Your monthly charging energy, in kWh, from your charger’s app totals, the car’s records or past session logs — plus an honest estimate of how much of it can move into the window.
If you are still working out how much energy your driving uses each month, our guide to how many kWh it takes to charge an EV is the starting point.
The Calculation, Worked at Example Rates
The rates in this table are examples chosen to make the arithmetic visible — read your own two rates off your tariff and re-run the same sums. The energy figures are examples too; substitute your app total.
| Comparison | Rates used (examples) | Energy shifted per month | Monthly difference |
|---|---|---|---|
| Off-peak instead of peak | 30¢ peak, 10¢ off-peak | 300 kWh | 300 × 20¢ = $60 saved |
| Off-peak instead of peak, lighter use | 30¢ peak, 10¢ off-peak | 150 kWh | 150 × 20¢ = $30 saved |
| Off-peak instead of a flat rate | 18.31¢ flat (U.S. average), 10¢ off-peak | 300 kWh | 300 × 8.31¢ ≈ $25 saved |
The formula never changes: saving = (rate you would have paid − off-peak rate) × kWh actually shifted. Our breakdown of what it costs to charge an electric car at home covers the all-in side of the same bill.
Three Things That Shrink the Real Saving
- Only energy inside the window earns the gap. A session that starts before the window opens bills its early energy at the earlier rate, so schedule the start, not just the plug-in.
- A time-of-use plan reprices the whole house. Cooking, laundry and heating at peak times pay the peak rate too; the plan comparison belongs to the tariff decision, covered in our guide to smart charging and time-of-use tariffs.
- Fixed charges do not move. The monthly customer charge and other flat fees are the same whatever hour you charge at — timing changes only the per-kWh part.
Set the Window Once
The method only pays if sessions actually start in the window, which is a scheduling job, not a memory job. The EVDANCE EV-ACT3204E 40A smart wall charger (9.6 kW, hardwired, ETL and FCC listed, SAE J1772, NEMA 4, WiFi app control, RFID cards) takes a scheduled start in its app, so the car waits for the cheap hours by itself. Other home options are on our residential EV charging page.
Frequently Asked Questions
Is off-peak electricity always half the price?
No. There is no standard ratio: gaps run from a couple of cents to several multiples, and some plans add a super off-peak tier that widens the gap further at the quietest hours. Only your tariff sheet answers the question for your address.
Does charging off-peak save anything on a flat rate?
No. A flat rate charges the same price at every hour, so timing changes nothing — the 18.31 cent U.S. average is a benchmark of that kind of plan. Timing only pays where two or more rates exist.
Where do I find my two rates?
On your plan’s tariff or rate sheet, or via the rate code printed on your bill. To see which EV and time-of-use plans exist in your state before switching, the DSIRE database lists programs by location.
Related Reading
- Smart Charging and Time-of-Use Tariffs: How Scheduling Cuts EV Charging Costs
- How Much Does It Cost to Charge an Electric Car at Home?
- How Many kWh Does It Take to Charge an EV?
