Tesla charging cost calculator
Last checked: 9 October 2026
In short: Cost of a home charge = battery capacity × (target % − current %) ÷ charging efficiency × your electricity price. Home AC charging loses roughly 10%, so a 75 kWh Tesla going from 20% to 80% draws about 50 kWh from the wall. Use the calculator below with your own numbers.
Work out what a home charge really costs, what you pay per 100 km or miles, and what a month of driving comes to. Everything runs in your browser; nothing is stored or sent.
How the calculation works
Energy added = battery capacity × (target % − starting %). Energy from the wall = that figure ÷ charging efficiency, because some energy is lost as heat and some goes to conditioning the battery. Cost = energy from the wall × your price per kWh. Cost per 100 km (or miles) uses your consumption in Wh, also divided by the efficiency.
Battery sizes in the list are approximate usable capacities and vary by model year and battery chemistry; if you know yours, type it in. A typical Model 3 or Y uses roughly 140 to 180 Wh per km (about 230 to 290 Wh per mile), more in winter and at motorway speed.
Want this for every real charge, automatically?
A calculator gives you an estimate. ConTess, our Mac app for Tesla, records every actual charging session and trip and prices each one at your own tariff, with separate day and night rates, plus phantom drain while parked and monthly and yearly totals. If you have a Tesla Wall Connector it also reads live power straight from it. It is a one-time purchase, with no subscription and no servers of ours.
Questions
How much does it cost to charge a Tesla at home?
Multiply the energy you add by your electricity price, then allow for charging losses of roughly 10% on home AC charging. Example: a 75 kWh battery from 20% to 80% adds 45 kWh, about 50 kWh from the wall; at 0.25 per kWh that is about 12.50 in your currency.
Why does a charge cost more than the kWh shown in the car?
Some energy is lost as heat in the charger and battery, and the car uses power to condition the battery while charging. On home AC charging that is typically around 10%, which is why the calculator divides by an efficiency figure you can change.
How can I track my real Tesla charging costs automatically?
ConTess, a Mac app for Tesla, prices every charging session and every trip at your own tariff, including separate day and night rates, and shows phantom drain and monthly totals. It is a one-time purchase.
Prices and availability of other apps were checked on 9 October 2026 and can change; check each vendor's own site before you buy. Spotted something out of date? Email support@contess.app and we will fix it.
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