Charging Calculator

Electric Vehicle Charging Time Calculator

If you want to figure out the time that it will take to charge the electric battery of your vehicle, then you are in the right place. Calculating charging time can be tricky as it includes mathematical calculations, which is something that a lot of people hate.

But we’ve made it easy for you, with all of the information that you need to know in one place and a calculator to help you do the maths. So let’s get started. 



Cost for full charge This is the cost for a full charge.


Cost for target charge This is the cost for a full charge.


User Inputs

Current charge(%) This is the current charged condition of the battery

Target charge(%) This is the desired charged condition of the battery. A full charge is 100%.

Charger Inputs

Charging efficiency(%) This efficiency ranges from 90% to 99%

Electricity cost($ per KW-Hr) Typical electricity costs vary from $0.12 to $0.20 per KW-Hr

Battery Inputs

Battery capacity(KW-Hr) Typical battery capacities range from 30 KW-Hr to 150 KW-Hr

Before we get into the mathematical equation that you need to use to work out the charging time for your electric vehicle, let’s look at the key things you need to consider.

The time that it will take to charge up your electric battery depends on 4 key factors: battery size, current/starting charge level, target charge level, and charging power. Just to clear up any confusion, let’s take a quick look at what all of these terms mean: 

Battery Size: Different electric vehicles will come with different battery sizes, you should input the number that is correct for your specific vehicle and its battery. Although battery size can be listed in a variety of different measurements, you must use kWh (kilowatt-hour) for this calculation. 

Current/Starting Charge Level: This is an important measurement to consider as it tells you how much energy is in the battery at the beginning of the charging process. Considering this figure is essential to avoid burning out the battery, or not charging it enough. This number comes in a percentage and corresponds to the existing power in the battery. If you are unsure how much power your battery has, and simply want to charge it to full, select 0% for this number. 

Target Charge Level: While the current/starting charge level looks at where your battery currently is, this number looks at where you want your battery to be. This number is simply the percentage that you want the battery to hit in terms of power. The majority of the time, this percentage will be 100%, but the most important thing is that the target charge level number always exceeds the current/starting charge percentage. 

Charging Power: The charging power for a vehicle should always be measured in kW (kilowatt), however, it is important to remember that this factor will always be influenced by the charging point that you are using or your vehicle itself. To figure this out, you should check the maximum charging power for both the charging point and your vehicle, then use the smallest number in the calculation. 

Once you have figured out all the numbers for these important factors, you can then substitute them into the equation. From there you will be able to work out the charging time. The equation we would recommend using is:

Charging Time = Battery Capacity                            Charge Power x 0.9

In short, the time it takes to charge the battery is equivalent to the size of the battery (kWh) divided by the charging power multiplied by 0.9. 

Cost to Charge an Electric Car Calculator

You may also want to calculate the cost of charging your electric car, which is why we’ve put together this guide. Similar to calculating charging time, calculating the charging cost can also be tricky. This guide has all the information you need to know, with a calculator to allow you to figure out how much it will cost to charge your electric car. 

Before we look at the equation that you need to use to figure this out, let’s first take a look at all the factors that you need to consider. The main things that you will need to know to be able to calculate the cost of charging your electric car are the electricity price from your supplier (price/kWh), the battery size of the EV, and charging efficiency.

To ensure that your calculations are 100% accurate, let’s quickly establish what all of these terms mean:

Electricity Price from your Supplier: This number is very important as it will be affected by either your electricity bill or the place where you charge your vehicle. Figuring out this number can be difficult as the number is not readily available like it is for gas prices. The best way to find this out is by either checking your electricity bill if you charge at home or by contacting the place where you charge your vehicle so that you get a specific number. The most important thing is that this number is measured in price/kWh to ensure that your calculations are correct. 

The Battery Size of the EV: This number corresponds with the full battery capacity of your vehicle. This number should be measured in kWh (Kilowatt-hour). 

Charging Efficiency: This is the efficiency of your battery when charging, and will be measured in a percentage. For the calculation, you simply need to use the charging efficiency percentage. 

Once you have figured out all of the numbers that apply to you, you simply need to substitute them into the formula to be able to figure out the cost to charge your electric car. The equation that we would recommend using is:

Cost of Charge ($) = Electricity Price (Price/kWh) x Battery Size of the EV (kWh)                Charging Efficiency (%)

As well as calculating the cost of the charge in general, you may wish to calculate the cost of charging your electric vehicle for a specific journey. To figure out this number you will need to consider some other factors, these include EV energy consumption (kWh/100 miles or kWh/100KM) and distance (what you want to calculate the distance for).

However, it is not just these factors that will impact the cost of charging your electric vehicle. There are lots of different things that will impact the charging cost of your vehicle which is why you must realize these calculations will never be 100% accurate.

That being said, they are a great way to estimate the cost of charging your vehicle in general, or for a specific journey. 

Michael Schuck