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ChargeMath

Time-of-Use Optimizer Calculator

Find the cheapest time to charge your EV on a Time-of-Use electricity plan. Compare peak, off-peak, and super-off-peak costs side by side.

Data last updated: March 2026

Time-of-Use (TOU) electricity plans charge different rates depending on when you use power. By charging your EV during off-peak or super-off-peak hours, you can cut charging costs by 50-75%. Most utilities define peak hours as 4-9 PM, with the cheapest rates available overnight.

60 kWh battery, 25 kWh/100mi

\u00A2/kWh

Your utility's peak electricity rate

\u00A2/kWh

Typically evenings and mornings

\u00A2/kWh

Cheapest overnight rate (if your plan has one)

When peak pricing begins

When peak pricing ends

35 miles
10 miles150 miles

Charging Cost Comparison

🔴Peak Charging
$91.88/month
🔵Off-Peak Charging
$31.50/month
🟢Super Off-Peak Charging
$21.00/month
💰Annual Savings (Off-Peak)
$725/year
🌙Annual Savings (Super Off-Peak)
$851/year
🔋Full Charge (Peak)
$21.0060 kWh
🔋Full Charge (Super Off-Peak)
$4.8060 kWh

24-Hour Rate Schedule

12 AM
3 AM
6 AM
9 AM
12 PM
3 PM
6 PM
9 PM
Peak (35\u00A2/kWh)
Off-Peak (12\u00A2/kWh)
Super Off-Peak (8\u00A2/kWh)

Optimal Charging Window

Charge between 11 PM and 6 AM (super off-peak) to pay just 8\u00A2/kWh instead of 35\u00A2/kWh. That saves you 77% on every charge, or $851/year. Set your EV or smart charger to start at 11 PM automatically.

Rate TierRateFull ChargeMonthlyAnnual
Peak35\u00A2/kWh$21.00$91.88$1,103
Off-Peak12\u00A2/kWh$7.20$31.50$378
Super Off-Peak8\u00A2/kWh$4.80$21.00$252

Understanding Time-of-Use Electricity Plans

Time-of-Use (TOU) plans divide the day into pricing tiers based on grid demand. Peak hours (typically 4-9 PM) have the highest rates because everyone is home using appliances, AC, and cooking. Off-peak hours have moderate rates, and super off-peak hours (typically 11 PM to 6 AM) offer the lowest rates when demand is at its minimum.

Why TOU Plans Are Ideal for EV Owners

EV charging is one of the most "shiftable" electricity loads in a household. Unlike cooking or laundry, you can plug in your car whenever you get home but delay the actual charging to start at 11 PM automatically. This means you get the full benefit of cheap overnight rates without changing your daily routine at all.

Setting Up Scheduled Charging

  • Tesla: Go to Charging > Schedule > set departure time or start time in the Tesla app. The car will wait until off-peak hours.
  • Most other EVs: Use the manufacturer's app (FordPass, myChevrolet, etc.) to set a charging schedule. Look for "Charge Scheduling" or "Preferred Charging Times."
  • Smart chargers: Products like ChargePoint Home Flex, Emporia, and Grizzl-E have built-in scheduling through their companion apps.
  • Contact your utility to confirm your exact TOU rate schedule. Many utilities have EV-specific TOU plans with even deeper off-peak discounts than standard TOU plans.

Maximizing Your Savings

Beyond shifting EV charging, consider running your dishwasher, laundry, and other heavy appliances during off-peak hours too. Some smart home systems can automate this scheduling. Also check if your utility offers an EV-specific rate plan, which often provides steeper overnight discounts than their standard TOU plan.

Frequently Asked Questions

A TOU plan charges different rates depending on the time of day. Peak hours (typically afternoon and early evening) have the highest rates, while off-peak and super-off-peak hours (overnight and early morning) offer significantly lower rates. Utilities use these plans to encourage shifting electricity usage away from high-demand periods.

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