Calculating your charging time is straightforward once you know the EV Charging Time formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the EV Charging Time Calculator.
What is EV Charging Time?
The EV Charging Time calculation tells you your charging time from a few simple inputs. The figure you are solving for here is the charging time.
The EV Charging Time formula
The core formula is:
Charging time = Battery capacity ÷ (Charger power × Charging efficiency ÷ 100)Here is what each input means:
- Battery capacity — a value measured in kWh. Example: 60 kWh.
- Charger power — a value measured in kW. Example: 7.4 kW.
- Charging efficiency — a percentage, such as an annual rate. Example: 9%.
How to calculate it step by step
- Write down the battery capacity (for example, 60 kWh).
- Write down the charger power (for example, 7.4 kW).
- Write down the charging efficiency (for example, 9%).
- Apply the formula above to get your charging time.
- Double-check the result with the EV Charging Time Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Battery capacity | 60 kWh |
| Charger power | 7.4 kW |
| Charging efficiency | 9% |
| Charging time | 9.01 |
With battery capacity of 60 kWh, charger power of 7.4 kW and charging efficiency of 9%, the charging time works out to 9.01.
Example 2
With battery capacity of 120 kWh, charger power of 7.4 kW and charging efficiency of 9%, the charging time works out to 18.02.
| Result | Value |
|---|---|
| Charging time | 18.02 |
Example 3
With battery capacity of 30 kWh, charger power of 7.4 kW and charging efficiency of 9%, the charging time works out to 4.50.
| Result | Value |
|---|---|
| Charging time | 4.50 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the EV Charging Time Calculator does it instantly, for free, with the formula and a worked example built in.
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