EV on a Time-of-Use Rate: The Whole-Home Net Calculator
Off-peak charging can save on the car and cost on the house — the net whole-home result on verified TOU tariffs, from your kWh, rates and charging window.
· Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23
On this page: CalculatorTableHow we calculatedSources
Jump to calculator ↓- TOU applies to
- Every kWh, not just the car
- Cold at 20°F
- −30 to −41% range (AAA, DOE, Recurrent)
- DCFC pricing
- No network publishes one flat rate
- EPA kWh/100mi
- Wall-side — charging loss included
- EV registration fee
- Up to $250+/yr depending on state
- Verdict driver
- Your on-peak household share
Why this number
EV savings = EV home kWh × (flat − off-peak) minus home exposure = household peak-window kWh × (on-peak − flat). Whether TOU wins depends less on the car than on how much of your household load you can keep out of the 4–9pm window. This tool computes both sides, adds fast-charging at its real price, applies the published cold-weather consumption penalty, and shows your state’s annual EV registration surcharge next to the result.Want the quick version first? The time-of-use rate simulator answers the flat-vs-TOU question in three inputs with real utility tariffs — this page is the deep end, with cold weather, fast charging and the whole house’s exposure.
Cheap overnight charging is the headline of every time-of-use pitch. The fine print is that the rate applies to your entire meter: the same plan that charges the car at 23¢ overnight bills the house at 54¢ between 4 and 9pm on PG&E’s EV plan, and at nearly 30¢ on Georgia Power’s. The car is the reason you switch; the house decides whether the switch pays.
This calculator nets the two against each other, using tariff figures read from the utilities’ own 2025–26 rate documents, the published cold-weather consumption penalty, fast-charging at the price you actually see in the app, and your state’s EV registration surcharge for context.
What the presets are — and are not
The three tariff presets are figures read directly from the utilities’ own rate documents, with their effective dates:
| Plan | Off-peak | On-peak | Window | As published |
|---|---|---|---|---|
| PG&E EV2-A (California) | 23¢ (12am–3pm) | 54¢ summer / 41¢ winter | 4–9pm every day | Rate sheet effective March 1, 2026 |
| Georgia Power TOU-OA-14 | 2.19¢ super off-peak (11pm–7am) | 29.79¢ (2–7pm weekdays, Jun–Sep) | summer weekday afternoons | Tariff effective January 2025 billing month — base rates; fuel and rider charges are added on top |
| APS TOU-E (Arizona) | 12.3¢ off-peak; 3.5¢ super off-peak (10am–3pm weekdays, Nov–Apr) | 34.4¢ summer / 32.5¢ winter | 4–7pm weekdays | Tariff effective March 8, 2024 |
Con Edison’s residential TOU is deliberately not a preset: the published 5.22¢ off-peak / 27.86¢ summer on-peak figures are delivery charges only — the market supply charge comes on top — so they are not comparable to the all-in numbers this tool needs. Southern California Edison’s TOU-D-PRIME and Xcel Minnesota’s EV rate could not be verified against the utilities’ own documents at the time of writing and are omitted rather than approximated.
Where the winter numbers come from
Three independent published measurements, one direction:
- AAA (February 2019): at 20°F with the cabin heater on, average driving range fell 41% versus 75°F across five EVs; at 95°F with air conditioning, 17%.
- AAA (May 2026): the follow-up study measured a 35.6% MPGe drop and 39% calculated range decrease at 20°F, and about 10% efficiency loss at 95°F.
- U.S. DOE Vehicle Technologies Office (program record, September 2024): BEV range decreased 41% at 20°F (dynamometer, cabin held at 72°F) and about 14% at 95°F.
- Recurrent (November 2025, 30,000+ vehicles): real-world telemetry is kinder — EVs retain about 78% of range at 32°F and 70% at 20°F, with the best models at 88% and the worst at 69%.
The tool defaults to the fleet figure (−30%) because that is what shows up on real bills; the lab figure (−41%) is the honest worst case for short trips with the heater on. A range loss of L means energy per mile rises by 1/(1−L)−1 — a 30% loss is +43% kWh per mile in those months, which is how the calculator applies it.
The number nobody publishes
The single most important input here — what share of your household load falls in the peak window — has no official published average. The U.S. EIA’s hourly data confirms residential demand peaks around 5–6pm in summer, and NREL’s End-Use Load Profiles dataset contains the 15-minute detail from which a share could be computed for any region, but no agency states a headline “X% of home load is on-peak” figure. So this tool refuses to pretend: the input defaults to a third, and the honest way to set it is your own smart-meter portal, which most TOU-eligible utilities provide. It is also the input most worth changing — every percentage point you move out of the window is billed at the off-peak price instead.
Sources
- AAA, Cold Weather Reduces Electric Vehicle Range (Feb 2019) — newsroom.aaa.com ; AAA temperature-impact study (May 1, 2026) — newsroom.aaa.com
- U.S. DOE Vehicle Technologies Office, Impact of Cold Ambient Temperature on BEV Performance, program record dated Sept 12, 2024 — energy.gov (PDF)
- Recurrent, Winter EV Range Loss (updated Nov 19, 2025; 30,000+ vehicles) — recurrentauto.com
- PG&E residential rate plan pricing sheet, effective March 1, 2026 — pge.com (PDF)
- Georgia Power tariffs TOU-OA-14 and TOU-REO-18, effective January 2025 billing month — georgiapower.com (PDF)
- APS Rate Schedule TOU-E, effective March 8, 2024 — aps.com (PDF)
- Con Edison, residential time-of-use page (delivery rates; supply additional) — coned.com
- Electrify America pricing (location-based, app-shown; Pass+ $7/mo ≈ 25% saving) — electrifyamerica.com
- Kansas Legislative Research Dept., States’ Fees for Electric and Hybrid Vehicles (Jan 17, 2025 compilation of NCSL data) — klrd.gov ; per-state statutes via DOE AFDC
- NREL, End-Use Load Profiles for the U.S. Building Stock — data.openei.org ; EIA hourly demand patterns — eia.gov
Retrieved September 2, 2026. Tariffs change on schedule and fees are indexed in several states — verify your own utility’s sheet and your state’s current fee before deciding. Estimate, not a quote.
Frequently asked questions
Why does a TOU rate affect my whole bill and not just EV charging?
Because with most utilities the time-of-use plan is a rate for the entire meter, not a separate price for the car. Every kilowatt-hour the house uses in the on-peak window — air conditioning at 5pm, cooking at 6pm, television at 8pm — is billed at the peak price that makes the overnight price possible. A household that uses a lot of power in the evening can lose more on the house than it saves on the car. Some utilities do offer separately-metered or managed-charging EV programs where only the charger gets the special rate; those change this arithmetic completely and are worth asking your utility about directly.
How much worse is an EV in winter, really?
The published measurements agree on the direction and roughly on the size. AAA’s laboratory testing found a 41% range loss at 20°F with the cabin heater running in its 2019 study, and a 39% calculated range decrease in its May 2026 follow-up. A U.S. Department of Energy program record dated September 2024 also reports 41% at 20°F. Recurrent’s telemetry across more than 30,000 real cars is kinder: about 70% of range retained at 20°F — a 30% loss — because real driving includes heat pumps, preconditioning and mixed conditions. This tool defaults to the fleet figure and lets you set anything between. The loss shows up on your bill as more kWh per mile, not as a stranded car.
What does DC fast charging actually cost in 2026?
There is no single answer, and that is the honest finding: Electrify America’s own pricing page no longer lists a national per-kWh rate — pricing is set per location and shown in the app, with a membership discount of about 25% for $7/month. Tesla prices per site and per time of day, and other-brand EVs typically pay a premium there unless they buy the monthly membership. EVgo prices vary by region and plan tier. Practically: check the app for the stations you would actually use and enter that number here. The default in this tool is only a placeholder in the middle of commonly seen prices.
Do I pay extra to register an EV, and does a TOU rate change that?
Most states now charge an annual EV registration surcharge — from around $50 in Hawaii to $200 or more in a dozen states, with Texas charging $400 on first registration and $200 at renewal, and Pennsylvania at $250 in 2026. The rate plan you choose has no effect on it; it is shown here because it belongs in any honest total-cost picture of EV ownership. The figures in this tool come from a January 2025 state legislative compilation of NCSL data — verify your own state’s current fee at registration time, as several states index these fees upward annually.
Should I add 10% for charging losses on top of the EPA figure?
No — and this is one of the most common double-counts in EV math online. The EPA kWh/100mi figure on the window sticker and fueleconomy.gov is measured wall-side: it is the energy drawn from your outlet, charging losses included. Adding another 10% on top counts the same loss twice and inflates every cost estimate downstream. Enter the EPA figure as-is.
How we calculated this
Monthly cost = Σ (kWh in each period × that period’s rate). Charging kWh = miles ÷ 100 × kWh/100 mi, placed in the period you charge in; the rest of the house is split across periods by the shares you set. The flat-rate comparison is total kWh × your flat rate; the saving is the difference.Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.