Plug-in Hybrid Economy Calculator

Plug-in hybrids run on electricity for short trips, cutting fuel costs.

How the Math Works

The calculator uses a two-part formula to estimate annual fuel costs for a plug-in hybrid electric vehicle (PHEV). First, it calculates the electric portion: multiply the miles driven in EV mode by the cost per mile for electricity (derived from electricity rate per kilowatt-hour and vehicle efficiency). Second, it calculates the gasoline portion: multiply the remaining miles (total annual miles minus EV miles) by the cost per mile for gas (derived from gas price per gallon and vehicle's MPG). These two values are added together to get the PHEV's total annual fuel cost, which is then compared to a gas-only vehicle's cost calculated using total miles and gas price/MPG.

Practical Applications

To use this calculator, input your annual mileage, the percentage or number of miles you expect to drive in EV mode, your electricity rate (per kWh), gas price (per gallon), and your vehicle's MPG for both electric and gasoline modes. The tool will automatically compute the split costs and compare them to a conventional gas car's fuel expenses, helping you evaluate whether a PHEV offers financial advantages based on your driving patterns and local energy prices.

Day-to-Day Use

This calculation empowers everyday drivers to make smarter financial decisions about vehicle purchases and fuel budgeting. By understanding how shifting between electric and gasoline modes affects costs, you can optimize your driving habits—like charging during off-peak hours or planning routes to maximize EV usage. It also clarifies long-term ownership expenses, helping you decide if a PHEV's higher upfront cost is justified by lower fuel bills, ultimately saving money and reducing reliance on fossil fuels.

Worked example

50 km/day with a 50 km EV range costs about $456/year vs $1916 for gas-only.

FAQ