Tesla Charging Cost Calculator

Estimate what a charging session will cost and how long it will take, based on your battery size, the charge percentage you're adding, your electricity rate, and charging efficiency.

Quick Facts

Formula
Cost = Battery kWh × (Target% − Current%) ÷ 100 ÷ Efficiency × Rate
Charging losses of roughly 10-15% mean the wall meter reads higher than the kWh added to the battery.

Your Results

Calculated
Estimated charging cost
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Total cost of this charging session
Energy added to battery
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kWh delivered from start to target charge
Energy drawn from grid
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Includes charging losses
Estimated charging time
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At your charger's power output

Ready

Set your battery, charge range, rate, and charger, then press Calculate.

About the Tesla Charging Cost Calculator

This calculator estimates the cost and time of a Tesla charging session using the standard energy-and-rate method that applies to any electric vehicle: the energy you add to the battery, adjusted for charging losses, multiplied by your electricity price.

The formula

Three steps turn your inputs into a cost and a time:

  • Energy added to the battery (kWh) = Battery capacity × (Target charge % − Current charge %) ÷ 100.
  • Energy drawn from the grid (kWh) = Energy added ÷ Charging efficiency. Charging is never 100% efficient — some energy is lost as heat in the cable, the onboard charger, and the battery's thermal management system — so the wall meter always reads a bit higher than what reaches the pack.
  • Total cost ($) = Energy drawn from the grid × Electricity rate ($/kWh).

Charging time is estimated separately as Energy added ÷ Charger power, assuming the charger delivers its rated power for the whole session. In practice, charge rate tapers as the battery fills — especially past about 80% on a DC fast charger like a Supercharger — so real sessions that go deep into the high percentages typically take longer than this straight-line estimate.

Getting accurate results

  • Use your Tesla's actual usable battery capacity (check the vehicle's specs or a trusted reference for your specific model and trim) rather than a rounded guess — a few kWh of error carries straight through to cost.
  • Charging efficiency is typically 85-92% for both home Level 2 charging and Supercharging; use a lower figure in cold weather, since battery preconditioning and heating draw extra energy.
  • Enter the electricity rate that actually applies: a flat home rate, a time-of-use off-peak rate, or the per-kWh Supercharger price for your account tier and vehicle.

Using the result

Compare the estimated cost per session against your driving habits to get a sense of cost per mile — divide the cost by your typical miles of range gained. Home charging on a standard residential rate is usually the cheapest option; public Level 2 and Supercharging usually cost more per kWh but save time. This estimate does not include Supercharger idle fees, membership discounts, or demand charges, since those vary by location and plan.

Frequently Asked Questions

What formula does this calculator use?
It multiplies your battery capacity by the percentage of charge you're adding, divides by charging efficiency to find the energy actually drawn from the wall, then multiplies by your electricity rate: Cost = (Battery kWh × (Target% − Current%) ÷ 100 ÷ Efficiency) × Rate per kWh.
Why does energy drawn from the grid exceed energy added to the battery?
Charging always loses some energy as heat in the cables, the onboard charger, and the battery management system. Typical Level 2 home charging and Supercharging are both roughly 85-92% efficient, so the wall meter reads higher than the kWh the battery actually gains.
How accurate is the estimated charging time?
The time estimate divides the energy you need to add by your charger's rated power output, assuming a constant charge rate. Real charging tapers as the battery approaches full, especially above about 80% on DC fast chargers, so actual time near the top of the range is usually longer than this straight-line estimate.
Does this include Supercharger idle fees or time-of-use rates?
No. Enter whatever per-kWh rate applies to your situation, whether that's a flat home rate, an off-peak time-of-use rate, or a Supercharger per-kWh price, and the calculator will use it directly. It does not add idle fees, membership discounts, or demand charges, since those vary by location and plan.

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