Calculadora de Custo de Recarga de Carro Elétrico
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
kWh = bateria × (1 - carga%/100); custo = kWh × tarifa
About this calculator
This calculator estimates the cost to recharge an electric vehicle from the current battery level to 100%. You input the total battery capacity in kWh, the current charge percentage, and the electricity rate per kWh. The calculation is straightforward: first determines the energy needed (kWh = battery capacity × (1 - current charge in decimal)), then multiplies that value by the rate to get the total cost. It does not account for charging losses, temperature variations, or charger efficiency.
Use this tool to plan your charging expenses, compare costs between different rates or times (such as time-of-use tariffs), and understand the financial impact of keeping the battery at low levels. For example, if your battery is 50 kWh and at 20%, you need 40 kWh to fill up. With a rate of $0.80/kWh, the cost will be $32.00. It is useful for electric vehicle drivers, fleet managers, or anyone curious about economic feasibility.
Cautions: electricity rates vary by region, tariff flags (green, yellow, red), and time of day (peak/off-peak). The calculation assumes 100% efficiency, but in practice there are losses of 5 to 15% due to heat and charger resistance. Also, the usable battery capacity may be slightly less than nominal. For greater accuracy, check the actual rate on your electricity bill and add a margin for losses.
Frequently asked questions
Does the calculation account for energy losses during charging?
No, it assumes 100% efficiency. In practice, losses of 5 to 15% occur due to heat and charger resistance. Adding a 10% margin is recommended for a more realistic estimate.
Does the electricity rate vary by time of day?
Yes, many utilities have different rates for peak and off-peak hours. Check your electricity bill or contact your provider to know the applicable rates.
Can I use this calculator for any electric vehicle?
Yes, as long as you know the battery capacity in kWh (found in the vehicle manual) and the current charge level. The calculation is universal for electric vehicles.
What is a tariff flag and how does it affect cost?
A tariff flag (green, yellow, or red) is an additional charge on the electricity bill set by the regulator. Higher flags increase the rate per kWh, raising the charging cost.
Is the battery capacity always the total capacity?
Usually yes, but some manufacturers reserve a portion for protection. Usable capacity may be slightly lower. Check the available capacity in the vehicle manual.