By EV Charge Cost Editorial Team. Published September 28, 2026, updated October 26, 2026.
Two fuels, two prices
A PHEV runs on electricity until its battery is depleted, then drives as a regular hybrid on gasoline. Your fuel cost is a blend of two numbers:
- Electric miles: kWh per 100 miles × your electricity price.
- Gas miles: gas price ÷ the car's mpg in hybrid mode.
The share of miles you drive on electricity decides where your bill lands. The EPA label for a PHEV lists both an electric consumption figure and a gasoline mpg; use your own model's numbers wherever you can.
An illustrative PHEV
Our vehicle data covers fully electric models, so for this guide we use an illustrative PHEV: electric consumption of 33.5 kWh/100 mi (the same as the typical EV in our data), 40 mpg in hybrid mode and 40 miles of electric range. Prices are the U.S. average electricity rate of 18.16¢/kWh (August 2026) and regular gasoline at $4.284 (week of 2026-10-19).
| Share of miles on electricity | Electricity | Gasoline | Total per year | Per month |
|---|---|---|---|---|
| 0% | $0.00 | $1,445.85 | $1,445.85 | $120.49 |
| 25% | $205.32 | $1,084.39 | $1,289.71 | $107.48 |
| 50% | $410.64 | $722.93 | $1,133.57 | $94.46 |
| 75% | $615.96 | $361.46 | $977.43 | $81.45 |
| 100% | $821.29 | $0.00 | $821.29 | $68.44 |
For comparison, a full EV at 33.5 kWh/100 mi costs $821.29 a year for the same miles, and a 30 mpg gas car costs $1,927.80.
When is plugging in worth it?
For the illustrative PHEV, electric driving is cheaper than hybrid mode whenever electricity costs less than about 32.0¢/kWh at $4.28 gas. That break-even is (gas price ÷ mpg) ÷ kWh per mile. Using each state's regional gas price, electricity is above the break-even in 2 states: Hawaii, Maine. There, on these assumptions, hybrid-mode miles are the cheaper fuel. A PHEV with better hybrid mpg raises the bar for electricity; a more efficient electric mode lowers it.
Time-of-use plans can move you well below the average price. See time-of-use rates and break-even electricity prices.
PHEV electric miles vs a full EV
Per electric mile, a PHEV and a full EV cost the same if their kWh per 100 miles is the same, because both pay your home rate. A PHEV carries an engine and fuel system too, so check its own electric rating rather than assuming it matches an EV. The practical difference is how many miles you can drive before gasoline takes over. On the illustrative 40-mile battery, a driver who covers 37 miles on an average day could, in principle, do most of it on electricity if they plug in nightly; longer days bring in the gas engine.
Location matters as much as for full EVs. Electric miles in the illustration cost $4.26 per 100 in Nevada and $15.81 in Hawaii.
Charging a PHEV at home
Small batteries make home charging easy. The illustrative 13.4 kWh charge takes about 9 h 19 min on a standard 120 V outlet at 1.44 kW, so an ordinary overnight plug-in often refills it. Level 2 is optional for many PHEV owners. Some PHEVs also limit their onboard charging speed, so a bigger charger may not help; see charging on a regular outlet.
Getting the most from a PHEV
- Plug in every night. Electric share is the biggest lever; a PHEV that is rarely charged is just a heavier hybrid.
- Use electric mode for short trips and save the gas engine for long ones.
- Track both fuels. Log kWh and gallons for a month to find your real electric share.
To compare a PHEV with a conventional hybrid, see EV vs hybrid fuel cost; to price a full EV in your state, use the charging cost calculator.