Home Energy
Electricity Cost Calculator
Estimate how much an appliance costs to run from its power rating, daily usage, and your electricity rate.
EV Charging Cost Calculator
Estimate electricity drawn from the grid and the cost of charging an EV between two battery levels.
Estimate one charging session using battery capacity, starting and target charge, electricity price, and expected charging efficiency.
Enter your details
Charging session details
Energy added to batteryElectricity drawn from gridCharging cost
Your estimate will appear here
Complete the fields and calculate to see a detailed result.
Estimating a charging session
Enter usable battery capacity when known, then the starting and target state of charge. Efficiency accounts for energy lost in charging equipment, battery conditioning, and vehicle electronics.
Formula and methodology
Battery energy added is capacity × (target % − starting %). Grid energy is battery energy ÷ efficiency. Charging cost is grid energy times the USD per-kWh rate.
Worked example
Charging a 75 kWh battery from 20% to 80% adds 45 kWh. At 90% efficiency, about 50 kWh comes from the grid. At $0.18 per kWh, estimated cost is $9.00.
Assumptions and limitations
Actual losses vary with charger type, speed, temperature, conditioning, vehicle behavior, and state of charge. Time-of-use prices, network session charges, taxes, and idle fees are excluded unless included in the entered rate.
Frequently asked questions
Why is grid energy higher than battery energy?
Charging equipment and the vehicle lose some energy as heat and supporting loads.
What efficiency should I use?
90% is a practical starting estimate; measured wall-to-battery data is better.
Does this include public charger fees?
No. Add session, time, tax, and idle fees separately.
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