United States version
How it works
Separate energy arriving in the battery from energy bought at the meter, and compare annual energy spending on the same driving distance.
This is the United States planning view, with monetary inputs and outputs in USD. A currency label does not establish that a tax rate, construction price, coverage rule or legal limit has been verified locally. The inputs and limitations below describe the actual scope.
Input query strings and outputs
Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.
Input query strings
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?unitSystem=Measurement systemChoice · Optional · Default: imperial · Accepted values: imperial, metric
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?batteryCapacity=Usable battery capacity, kWhNumber · Required · Default: 60
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?startPercent=Starting state of chargePercentage · Required · Default: 20
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?endPercent=Target state of chargePercentage · Required · Default: 80
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?wallPower=Average sustained wall charging power, kWNumber · Required · Default: 7
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?annualDistance=Annual driving distanceNumber · Required · Default: 12,427.423844746678
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?evConsumption=Vehicle battery consumptionNumber · Required · Default: 28.968192
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?chargeEfficiency=Wall-to-battery charging efficiencyPercentage · Required · Default: 90
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?electricityRate=Electricity price per wall kWhMoney · Required · Default: 0.2
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?fuelConsumption=Comparison fuel consumptionNumber · Required · Default: 2.976005952012
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?fuelPrice=Fuel price per volume unitMoney · Required · Default: 6.0566588544
Outputs
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batteryAddedEnergy added to battery, kWhNumber
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wallEnergyPurchased wall electricity, kWhNumber
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chargeCostModeled charging-session costCurrency · Currency: USD
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hoursIdealized charging time, hoursNumber
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wallKwhAnnual wall electricity, kWhNumber
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evEnergyCostAnnual EV charging costCurrency · Currency: USD
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fuelEnergyCostAnnual comparison fuel costCurrency · Currency: USD
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energySavingAnnual energy-cost savingCurrency · Primary output · Currency: USD
Formula
wall energy = usable battery capacity × state-of-charge increase ÷ charging efficiency.
Calculations retain numeric precision internally. Displayed values are rounded for readability. Quantities that must be purchased as whole units are rounded up only where the formula explicitly requires it.
Read the inputs before calculating
- Usable battery capacity, kWh: Enter the quantity described by the label.
- Starting state of charge: Enter the quantity described by the label.
- Target state of charge: Enter the quantity described by the label.
- Average sustained wall charging power, kW: Enter the quantity described by the label.
- Annual driving distance: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Vehicle battery consumption: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Wall-to-battery charging efficiency: Enter the quantity described by the label.
- Electricity price per wall kWh: Enter the quantity described by the label.
- Comparison fuel consumption: Enter the quantity described by the label. The measurement selector converts this physical quantity; it does not change the underlying scenario.
- Fuel price per volume unit: Enter the quantity described by the label. This is a price per displayed unit, so the price converts inversely to the physical quantity.
Reproducible worked example
The following is a fictional arithmetic example, not a local quote, a verified claimant or a market forecast. Its values are included so the formula can be checked. The form does not automatically confirm any verification checkbox.
| Input | Example value |
|---|---|
| Usable battery capacity, kWh | 60 |
| Starting state of charge | 20 |
| Target state of charge | 80 |
| Average sustained wall charging power, kW | 7 |
| Annual driving distance (mi) | 12,427.4238 |
| Vehicle battery consumption (kWh/100 mi) | 28.9682 |
| Wall-to-battery charging efficiency | 90 |
| Electricity price per wall kWh | 0.2 |
| Comparison fuel consumption (US gal/100 mi) | 2.976 |
| Fuel price per volume unit (/US gal) | 6.0567 |
| Output | Calculated result |
|---|---|
| Energy added to battery, kWh | 36 |
| Purchased wall electricity, kWh | 40 |
| Modeled charging-session cost | USD 8 |
| Idealized charging time, hours | 5.7143 |
| Annual wall electricity, kWh | 4,000 |
| Annual EV charging cost | USD 800 |
| Annual comparison fuel cost | USD 2,240 |
| Annual energy-cost saving | USD 1,440 |
Interpreting a changed assumption
Start with one complete scenario and change only one input when diagnosing a difference. Recheck units, the period of every rate, whether an amount is recurring or one-off, and whether a cost is already included elsewhere. A larger calculated benefit is not evidence that an assumption is more likely to occur.
Limitations
- Prices, consumption and contract terms are entered scenarios. This is not a retail quote, tax eligibility determination or vehicle safety certification.
- Charging time assumes the entered sustained average wall power, not the charger peak rating. Tapering, battery conditioning, standby, session fees and time-based billing need separate allowances. Imperial fuel quantities are US gallons, never UK imperial gallons.
Frequently asked questions
What does this EV Charging Cost and Time result represent?
Separate energy arriving in the battery from energy bought at the meter, and compare annual energy spending on the same driving distance. It applies the displayed formula to your inputs; it does not infer omitted facts.
Are the starting amounts verified United States prices or legal rules?
No. Numeric defaults are illustrative unless an input or dated reference explicitly identifies a researched component. Currency is USD; local quotes, eligibility and unsupported rules must be entered and verified separately.
What must I check before relying on the result?
Prices, consumption and contract terms are entered scenarios. This is not a retail quote, tax eligibility determination or vehicle safety certification.
Can I compare or share different assumptions?
Change one assumption at a time and use the browser-local project or share controls. A shared URL contains the encoded input values; do not include information you do not wish to disclose.
Sources and reference scope
- DOE energy-use arithmetic — retrieved 2026-09-24. Energy consumption versus power; not a local tariff or an approval of this implementation.
- NIST unit conversion guidance — retrieved 2026-09-24. Unit definitions; geometry and financial arithmetic in these worksheets are explicitly stated.
- CFPB loan-estimate explanation — retrieved 2026-09-24. US cost components; the general amortization formula is stated separately.
These references support only their stated scope. They are not evidence that every local rule or price needed by the master expansion has been loaded.