Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Cost to charge at home
$8.00
Cost at a public fast charger
$24.00
Energy added to the battery (kWh)
45.0
Energy drawn from the grid (kWh)
50.0
Range added (miles)
158
Home charging cost per mile
$0.051
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter battery capacity (kwh).
- 2Enter charge from (%).
- 3Enter charge to (%).
- 4Enter home rate per kwh ($).
- 5Enter public dc fast rate per kwh ($).
- 6Enter charging losses (%).
- 7Enter miles per kwh.
- 8Read your cost to charge at home on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
Charging losses are real: expect 8–12% of the energy you pay for never to reach the battery, more in cold weather and on AC home chargers.
Worked example
Using the values the calculator loads with:
Inputs
- Battery capacity (kWh): 75
- Charge from (%): 20
- Charge to (%): 80
- Home rate per kWh: 0.16 $
- Public DC fast rate per kWh: 0.48 $
- Charging losses: 10 %
- Miles per kWh: 3.5
Results
- Cost to charge at home: $8.00
- Cost at a public fast charger: $24.00
- Energy added to the battery (kWh): 45
- Energy drawn from the grid (kWh): 50
- Range added (miles): 157.5
- Home charging cost per mile: $0.051
What each field means
Inputs
- Battery capacity (kWh)
- The battery capacity (kwh) used in the calculation. Starts at 75 so you have a working example on load.
- Charge from (%)
- The charge from (%) used in the calculation. Starts at 20 so you have a working example on load. Accepted range: 0–100.
- Charge to (%)
- The charge to (%) used in the calculation. Starts at 80 so you have a working example on load. Accepted range: 0–100.
- Home rate per kWh ($)
- The home rate per kwh used in the calculation, measured in $. Starts at 0.16 $ so you have a working example on load.
- Public DC fast rate per kWh ($)
- The public dc fast rate per kwh used in the calculation, measured in $. Starts at 0.48 $ so you have a working example on load.
- Charging losses (%)
- The charging losses used in the calculation, measured in %. Starts at 10 % so you have a working example on load. Accepted range: 0–30 %.
- Miles per kWh
- The miles per kwh used in the calculation. Starts at 3.5 so you have a working example on load.
Results
- Cost to charge at home
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cost at a public fast charger
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Energy added to the battery (kWh)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Energy drawn from the grid (kWh)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Range added (miles)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Home charging cost per mile
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the ev charging cost calculator work?
Charging losses are real: expect 8–12% of the energy you pay for never to reach the battery, more in cold weather and on AC home chargers. The underlying maths is: Cost = Battery kWh × (% added) ÷ efficiency × price per kWh.
What do I need to enter?
7 values: battery capacity (kwh), charge from (%), charge to (%), home rate per kwh, public dc fast rate per kwh, charging losses, and miles per kwh. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the cost to charge at home result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). EV Charging Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/ev-charging-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/ev-charging-cost" target="_blank" rel="noopener">EV Charging Cost Calculator — RevenueLab</a> (2026).</p>
Source: [EV Charging Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/ev-charging-cost) (2026).