EV Off-Peak Charging: How Much Can You Save?

Switching to a time-of-use (TOU) electricity plan and charging your EV overnight is one of the easiest ways to cut your fueling cost — often nearly in half. On a TOU plan, the price you pay per kWh changes with the time of day: expensive during peak hours, cheap during off-peak hours overnight. Since most EVs sit parked at home all night anyway, you can schedule charging to land entirely in the cheap window and pay the lowest rate your utility offers — with no change to how you drive.

Here's the short version. A flat-rate plan charges the same price for every kWh, around the clock. A time-of-use plan splits the day into pricing tiers — typically peak (high demand, high price) and off-peak (low demand, low price), sometimes with a mid-peak tier between them. If your off-peak rate is, say, 12¢/kWh versus a flat rate of 20¢/kWh, every kWh you move into the off-peak window saves 8¢. Over a year of charging, that adds up to real money. The catch: TOU rates apply to your whole home, so the savings only hold if your other usage doesn't pile up during expensive peak hours.

How time-of-use rates work

On a flat-rate plan, electricity is one price all day. On a time-of-use plan, your utility divides the 24-hour day into blocks and prices each block differently based on grid demand:

• Peak — the most expensive hours, usually late afternoon through evening when household and business demand spikes.
• Off-peak — the cheapest hours, usually overnight when demand is low.
• Mid-peak (on some plans) — a middle price for the shoulder hours between the two.

The exact hours and prices vary by utility, by season, and sometimes by whether it's a weekday or weekend. Many utilities also offer a dedicated EV time-of-use plan with an especially deep overnight discount, designed specifically to encourage home charging when the grid has spare capacity. You'll find your specific windows and prices on your utility's rate page or your bill — and you can compare typical residential prices on our electricity rates page.

The key insight for EV owners: off-peak almost always means overnight, and overnight is exactly when your car is parked and plugged in. That alignment is what makes the savings nearly free to capture.

The savings math

Your annual savings from charging off-peak come down to one formula:

Annual savings = annual charging kWh × (your normal rate − off-peak rate)

First, figure out how much energy your EV uses in a year:

Annual EV kWh = (annual miles ÷ efficiency in mi/kWh) × ~1.1

The ~1.1 accounts for roughly 10% charging losses — the energy that goes into heat and the charging process rather than the battery. For a typical EV driven 12,000 miles a year at 3.5 mi/kWh:

• 12,000 ÷ 3.5 = 3,429 kWh into the battery
• × 1.1 for losses = ~3,770 kWh drawn from the wall

Now apply the rate difference. Say your flat rate is 20¢/kWh and your off-peak rate is 12¢/kWh — a gap of 8¢/kWh:

• 3,770 kWh × $0.08 = ~$302 saved per year

That's roughly $25 a month for changing nothing but when you charge. The bigger the gap between your peak/flat rate and the off-peak rate, the bigger the win.

Illustrative annual savings by rate gap

The table below shows annual savings for that same ~3,770 kWh/year driver under different rate scenarios. All numbers are illustrative examples, not quoted rates — plug in your own off-peak and normal rates to see your figure.

Drivers in high-rate regions, or those who put on more miles, see the largest savings — the math scales directly with both your annual kWh and your rate gap. To run the numbers for your exact car, mileage, and rates, use the EV charging cost calculator at the bottom of this page, or browse the cost to charge by EV model for per-model efficiency figures.

How to schedule off-peak charging

Capturing the savings is just a matter of telling your car or charger when to draw power. You don't have to be awake or remember to plug in at a specific minute — set it once and forget it. Two reliable ways:

1. Use the car's built-in schedule. Nearly every modern EV lets you set a charging window or a "ready by" departure time from the dashboard or the manufacturer's app. Set the start time to the beginning of your off-peak window.
2. Use a smart Level 2 charger's schedule. Many wall chargers have their own scheduling, often in a companion app. This is handy if your car's scheduling is limited, or if you want the charger to enforce the timing regardless of vehicle settings.

Pick one of the two — don't set conflicting schedules on both the car and the charger, or they can cancel each other out and skip a charge. Set the start time to the start of off-peak, and make sure the window is long enough to deliver the energy you need. A typical overnight off-peak window is several hours long, which is plenty for most daily top-ups, especially on Level 2. If you're charging on a slower connection or need a big charge, check that the off-peak hours actually cover the time required — our guide on how long it takes to charge an EV helps you estimate the hours.

Tip: Schedule charging to start at the off-peak boundary, not to finish by it. A "ready by 7 a.m." setting may pull some energy at peak rates to hit the deadline. Starting at the off-peak boundary keeps every kWh in the cheap window.

The whole-home caveat

Here's the part most off-peak guides skip: a time-of-use plan changes the price of everything in your home, not just the EV.

Moving your charging to off-peak is a clear win. But if your household uses a lot of electricity during peak hours — running central air conditioning through a hot afternoon, electric heat in the evening, cooking, or running the dryer right after work — those kWh now cost the higher peak rate. That extra cost can eat into, or even exceed, what you save on charging.

Before switching plans, weigh the whole-home picture:

• TOU usually wins if your non-EV usage is already mostly overnight or in cheaper hours, or you can shift big loads (laundry, dishwasher, pool pump) to off-peak.
• A flat rate may be cheaper if you have heavy, unavoidable peak-hour usage — for example, high summer AC load in a hot climate that runs all afternoon.

Most utilities let you look at your past usage by hour, and some offer a tool to estimate your bill under each plan. Do that comparison before you switch. The EV savings are real, but they're only the EV slice of a bill that covers your whole house.

The bottom line

Time-of-use plans price electricity by the hour — cheap overnight, expensive in the late-afternoon and evening peak. Because your EV parks at home all night, you can schedule charging entirely into the cheap off-peak window and cut your fueling cost substantially, often $300 or more a year for a typical driver, with no change to how you drive. Just remember TOU rates apply to your whole home: confirm your non-EV usage won't pile up during peak hours, schedule charging to start at the off-peak boundary, and let the car do the rest.

Want real numbers for your car, mileage, and rates? Use the calculator below to estimate what a charge actually costs, or browse more EV charging guides to dial in your setup.