Plug-in Hybrid Economy Calculator

A plug-in hybrid electric vehicle (PHEV) has both a gasoline engine and a battery pack that can be charged from an external power source. It runs on electricity first, then switches to gasoline once the battery is depleted. This makes PHEVs most efficient for short daily trips that stay within the electric-only range, while still offering the flexibility of a conventional car for longer journeys.

MPGe (miles per gallon equivalent) is a standardized metric that converts electrical energy consumption into a gasoline-equivalent figure, using the EPA's equivalence of 33.7 kWh per gallon of gasoline. For a PHEV, real-life MPGe is calculated by dividing total miles driven by the combined energy consumption from both electricity and gasoline. The more electric miles you drive relative to gas miles, the higher your MPGe will be.

Yes, in most cases — especially if you charge frequently and your daily commute falls within or near the battery-only range. The key savings come from substituting cheaper electricity for more expensive gasoline. The break-even point depends on your electricity rate, gas price, how often you charge, and how many miles you drive. Use this calculator to see your specific monthly and annual savings.

Charging frequency directly determines how many of your daily miles are powered by electricity versus gasoline. If you charge every day and drive fewer miles than your electric range, you could run almost entirely on electricity. Charging less often means more miles on gas, which reduces your effective MPGe and increases your monthly fuel spending significantly.

Once the battery is fully depleted, a PHEV operates like a conventional hybrid or regular gasoline car, relying entirely on its internal combustion engine. Its fuel economy at that point is simply its rated gas-only MPG. This is why PHEVs deliver the greatest savings for drivers who make frequent short trips and charge regularly — long highway trips without charging yield no electric benefit.

It depends on your driving patterns and access to charging. A PHEV is a strong choice if you have a short daily commute but occasionally need long-range capability without range anxiety. A fully electric vehicle (EV) is better if you have reliable charging at home and don't regularly make very long trips. PHEVs also make sense in areas where charging infrastructure is limited.

Use the average cost per kilowatt-hour (kWh) from your home electricity bill. The U.S. national average is around $0.16/kWh, but rates vary significantly by state and utility provider — from under $0.10/kWh in some states to over $0.30/kWh in others. If you charge at a public fast charger, the effective rate is usually higher, so factor that in if you rely on public charging.

The results are estimates based on the inputs you provide and standard energy equivalence formulas used by the EPA. Real-world fuel economy can vary due to driving style, temperature, terrain, AC usage, and vehicle age. For the most accurate picture, track your actual electricity and gas consumption over several months and compare to these estimates.