Home charging is usually the cheapest way to fuel an electric car; public fast chargers can cost several times more per kWh. About 10% of the energy is lost as heat while charging, and most owners charge to 80–90% for everyday use to look after the battery.
How to use the EV Charging Cost Calculator
- Car
- Battery capacity
- Efficiency
- Current charge level
- Target charge level
- Electricity price
- Charging efficiency
- Distance to drive
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose your car (or enter its battery size and efficiency), set the current and target charge levels, the price per kWh and the distance you drive.
Tips
- Use your own measured figures – fuel economy, speed and prices vary a lot with driving style, traffic, load and season.
- Pick the unit in each field’s menu (miles or kilometres, mpg or L/100 km); the calculator converts everything for you.
- Fill up to the brim twice and divide the distance by the fuel added to measure real fuel economy.
- For vehicle modifications, treat results as a starting point and confirm with the parts maker or a professional mechanic.
Common mistakes to avoid
- Mixing US and imperial (UK) gallons – a UK gallon is about 20% bigger.
- Using the advertised fuel economy instead of real-world figures.
- Forgetting tolls, parking and wear and tear when comparing driving with public transport.
Inputs explained
| Field | What to enter |
|---|---|
| Car | Choose one: Tesla Model 3 RWD (≈ 57.5 kWh, 25 kWh/100 mi), Tesla Model 3 Long Range (≈ 75 kWh, 26), Tesla Model Y Long Range (≈ 75 kWh, 28), Tesla Model S (≈ 100 kWh, 28) … |
| Battery capacity | In kWh |
| Efficiency | In kWh/100 mi |
| Current charge level | In % |
| Target charge level | In % |
| Electricity price | Units: /kWh |
| Charging efficiency | In % |
| Distance to drive | Units: mi, km, m, nmi |
What each result means
- Energy drawn from the grid = [Battery capacity used]×max([Target charge level] – [Current charge level], 0)÷100÷([Charging efficiency]÷100)
- Charging cost = [Energy drawn from the grid]×[Electricity price]
- Cost of a full charge (0–100%) = [Battery capacity used]÷([Charging efficiency]÷100)×[Electricity price]
- Cost per 100 miles = [Efficiency used]×[Electricity price]÷([Charging efficiency]÷100)
- Cost for the distance = [Distance to drive]÷1609.344÷100×[Cost per 100 miles]
Example values
How the main result changes when Battery capacity changes and everything else stays at the example values above:
| Battery capacity (kWh) | Charging cost |
|---|---|
| 37.5 | 8 |
| 56.25 | 8 |
| 75 | 8 |
| 93.75 | 8 |
| 112.5 | 8 |
| 150 | 8 |
Formula
Energy to add = capacity × (target − current level) ÷ charging efficiencyCharging cost = energy × price per kWhCost per 100 mi = efficiency (kWh/100 mi) × price ÷ charging efficiencyWorked example
Inputs — Car: Tesla Model 3 Long Range (≈ 75 kWh, 26); Battery capacity: 75 kWh; Efficiency: 27 kWh/100 mi; Current charge level: 20 %; Target charge level: 80 %; Electricity price: $0.16 /kWh; Charging efficiency: 90 %; Distance to drive: 1,000 mi.
Results — Battery capacity used = 75 kWh; Efficiency used = 26 kWh/100 mi; Energy drawn from the grid = 50 kWh; Charging cost = $8.00; Cost of a full charge (0–100%) = $13.33; Cost per 100 miles = $4.62; Cost for the distance = $46.22.
Frequently asked questions
How much does it cost to charge a Tesla?
A Model 3 Long Range from 20% to 80% uses about 50 kWh from the wall – around $8 at $0.16/kWh.
Is charging cheaper than petrol?
At home, usually: about 4–5 cents per mile versus 10–15 cents for a 25–35 mpg petrol car.
Why charge only to 80%?
Lithium-ion batteries age more slowly when not kept full; charge to 100% before long trips.
What formula does the EV Charging Cost Calculator use?
Energy to add = capacity × (target − current level) ÷ charging efficiency.