Tesla Charge Cost Calculator
Updated .
This calculator turns the energy added in one charge and your own price per kWh into three numbers: the cost of that charge, the cost per mile or kilometre driven on it, and a monthly estimate from how many times you charge. You can add a charging-loss percentage if you know one for your setup. Every figure is yours; the tool supplies only the arithmetic.
How it works
The calculator uses four steps, all shown here so you can repeat them on paper:
- Energy from the supply = energy added ÷ (1 − loss ÷ 100). With a loss of 0 this is just the energy added.
- Cost of the charge = energy from the supply × your price per kWh.
- Cost per mile or km = cost of the charge ÷ distance driven on that energy.
- Monthly estimate = cost of the charge × charges per month.
About the loss figure. Charging is not perfectly efficient, so the energy you are billed for at home can be higher than the energy the car reports adding. The calculator defines loss as the share of the energy drawn that never reaches the battery. If you can compare a home meter or smart-charger reading with the kWh your car says it added, the gap divided by the meter reading is your loss percentage. If you cannot measure it, leave it at 0 and treat the result as a lower bound. This site does not supply a typical loss figure because it varies with the charger, the supply and conditions.
About the price. Use what you actually pay. On a time-of-use home tariff, use the rate for the hours you charge in. At a public charger, use total paid ÷ kWh so that session or time-based fees are included. The distance is only as good as the match between the energy and the miles it covered, so for a steadier figure run the tool on several charges and average the results.
Worked example
Suppose a charge adds 40 kWh at a hypothetical price of 0.15 per kWh. The driver compared a home meter with the car’s summary and decides to enter a 10% loss. They drove 150 miles since the previous charge and charge about 8 times a month.
Energy from the supply: 40 ÷ (1 − 0.10) = 44.44 kWh. Cost of the charge: 44.44 × 0.15 = 6.67. Cost per mile: 6.67 ÷ 150 = 0.044. Monthly: 6.67 × 8 = 53.33.
With the loss left at 0, the same inputs give 40 kWh, a charge cost of 6.00, 0.040 per mile and 48.00 a month. The difference, about 5.33 a month, is the cost of the energy that never reached the battery, which is why it is worth measuring once if you charge at home most days. These numbers are illustrative arithmetic, not a statement about any Tesla model, tariff or charger.
Frequently asked questions
Do I have to enter a charging loss?
No. It is optional and defaults to 0. If you leave it at 0 the result is a lower bound, because some energy drawn from the supply may not reach the battery.
Where do I find the kWh added?
Look at the charging summary on the car’s screen or the session screen of the charger you used. Names and locations differ between models and software releases, so check your owner’s manual if you cannot find it.
How do I find my price per kWh?
At home, read it from your electricity bill or tariff, and use the rate for the hours you charge. At a public charger, divide the total you paid by the kWh delivered so that any time-based or session fees are included.
Why is my cost per mile different from last month?
Energy use per mile changes with speed, temperature, wind and hills, and so does the share of charging that happens on a cheaper or dearer tariff. Averaging several charges gives a steadier figure than any single one.
Does this send my numbers anywhere?
No. The calculation runs in your browser and nothing is stored or sent.
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