This estimator calculates the out-of-pocket energy cost of a public EV charging session. It supports per-kilowatt-hour pricing, a session fee, time-based parking or occupancy charges, taxes, and charging losses so the displayed total better reflects the amount paid for usable battery energy.
Drivers can compare charging networks or station types and see the effective cost per usable kilowatt-hour and per mile of range. The result depends on the fees entered; idle fees, membership discounts, demand-based pricing, and temporary promotions should be added only when they apply to the session.
1. Enter delivered energy
Use the charger receipt or planned session energy.
2. Add the energy price
Enter the station’s price per kilowatt-hour.
3. Include fixed and time fees
Enter only fees that apply to this session.
4. Set the tax rate
Use zero when taxes are already included.
5. Describe efficiency and consumption
These values support usable-energy and per-mile results.
6. Review total and unit costs
Compare the full session total, cost per usable kWh, and cost per mile.
Energy charge = Delivered energy × Price per kWh
Time charge = Billable minutes × Time-based fee
Subtotal = Energy charge + Session fee + Time charge
Total cost = Subtotal × (1 + Tax rate)
Usable battery energy = Delivered energy × Efficiency
Cost per mile = Total cost ÷ (Usable energy ÷ Consumption × 100)
The main result is the estimated amount charged for the complete session.
The calculation uses the entered fee structure and does not automatically retrieve station pricing.
Given: 42 kWh at $0.48/kWh, $1 session fee, 35 minutes at $0.10/minute, 8.25% tax, 92% efficiency, and 30 kWh/100 mi.
Calculation: Energy charge = 42 × $0.48 = $20.16. Time charge = 35 × $0.10 = $3.50. Subtotal = $20.16 + $1.00 + $3.50 = $24.66. Tax-adjusted total = $24.66 × 1.0825 = $26.69.
Result: Usable energy = 42 × 0.92 = 38.64 kWh, which supports about 128.8 miles. Cost per mile = $26.69 ÷ 128.8 = $0.207.
The estimated session cost is $26.69.
Yes, when you expect to remain connected after charging or the station bills occupancy time. Add them through the time-based fee and billable minutes fields.
Enter 0% tax to avoid counting it twice.
The charger may bill wall energy while the battery receives less because of conversion and thermal losses. Efficiency helps estimate usable energy and cost per mile.
Yes, but use the same basis. Include relevant home electricity rates and losses when comparing with a home energy-cost calculator.
Only if you allocate a portion of the subscription to the session and enter it as the session fee. Otherwise it is excluded.