EV charger amp to kW
Convert the charger current to kW and see how long it takes to charge your car from one battery level to another.
Inputs
Charging session
How EV charger amp to kW calculator works
The EV charger amp to kW calculator converts charger current into charging power in kilowatts (kW) and charge time with 6 inputs: current, voltage, phase, battery size, start and target charge, and charging efficiency.
t = E / (P × η)A 32 A charger at 230 V delivers 7.36 kW and charges a 60 kWh battery from 20% to 80% in 5.4 hours at 90% efficiency.
EV charger amp to kW formula
The EV charger amp to kW formula is P(kW) = I(A) × V(V) / 1,000 for a single-phase charger. There are 3 electric vehicle (EV) charging formulas: single-phase power, three-phase power and charge time.
Single-phase charger
P = I × V / 100032 A × 230 V / 1,000 = 7.36 kW
Three-phase charger
P = √3 × I × V / 10001.732 × 16 A × 400 V / 1,000 = 11.09 kW
Charge time
t = E / (P × η)36 kWh / (7.36 kW × 0.9) = 5.43 h
SAE J1772 defines Level 1 charging at 120 V up to 16 A (1.9 kW) and Level 2 charging at 208–240 V up to 80 A (19.2 kW). IEC 61851 covers Mode 3 AC charging up to 32 A three phase (22 kW) in Europe.
EV charger amp to kW conversion chart
The EV charger amp to kW conversion chart lists 11 charger currents from 6 A to 80 A with power at 120 V, 230 V and 240 V single phase and 400 V three phase, plus the 20–80% charge time for a 60 kWh battery at 230 V.
| Amps | 120 VkW | 230 VkW | 240 VkW | 400 V 3φkW | 60 kWhh @230 V |
|---|---|---|---|---|---|
| 6 A | 0.72 | 1.38 | 1.44 | 4.16 | 28.99 |
| 10 A | 1.2 | 2.3 | 2.4 | 6.93 | 17.39 |
| 13 A | 1.56 | 2.99 | 3.12 | 9.01 | 13.38 |
| 16 A | 1.92 | 3.68 | 3.84 | 11.09 | 10.87 |
| 20 A | 2.4 | 4.6 | 4.8 | 13.86 | 8.7 |
| 24 A | 2.88 | 5.52 | 5.76 | 16.63 | 7.25 |
| 32 A | 3.84 | 7.36 | 7.68 | 22.17 | 5.43 |
| 40 A | 4.8 | 9.2 | 9.6 | 27.71 | 4.35 |
| 48 A | 5.76 | 11.04 | 11.52 | 33.26 | 3.62 |
| 63 A | 7.56 | 14.49 | 15.12 | 43.65 | 2.76 |
| 80 A | 9.6 | 18.4 | 19.2 | 55.43 | 2.17 |
A 48 A Level 2 charger at 240 V delivers 11.52 kW.
EV charger amp to kW Excel formula
The EV charger amp to kW Excel formula is =A2*B2/1000 with amps in A2 and volts in B2. Use =C2/(D2*0.9) with kWh needed in C2 and charger kW in D2 for charge time.
| A | B | C | D | E | |
|---|---|---|---|---|---|
| 1 | Amps | Volts | PF | kW | Formula in D |
| 2 | 32 | 230 | 1 | 7.36 | =ROUND(A2*B2*C2/1000,2) |
| 3 | 48 | 240 | 1 | 11.52 | =ROUND(A3*B3*C3/1000,2) |
| 4 | 32 | 400 | 1 | 22.17 | =ROUND(SQRT(3)*A4*B4*C4/1000,2) |
Row 4 is a 22 kW three-phase wallbox.
EV charger amp to kW equation
The EV charger amp to kW equation is P = I × V / 1,000, and the charge time equation is t = E / (P × η).
- t
- Charge time in hours (h)
- E
- Energy needed in kWh
- P
- Charger power in kW
- η
- Charging efficiency, about 0.9
Energy needed equals battery size × (target % − start %): 60 kWh × (80% − 20%) = 36 kWh.
EV charger amp to kW FAQ
How many kW is a 32 amp EV charger?
A 32 amp EV charger is 7.36 kW at 230 V, 7.68 kW at 240 V and 22.17 kW three phase at 400 V.
How many kW is a 16 amp EV charger?
A 16 amp EV charger is 3.68 kW at 230 V single phase and 11.09 kW three phase at 400 V.
How long does a 7 kW charger take to charge 60 kWh?
A 7 kW charger takes 9.5 hours to charge 60 kWh from empty and 5.7 hours from 20% to 80%, at 90% efficiency.
What is Level 2 EV charging?
Level 2 EV charging is AC charging at 208–240 V and up to 80 A, giving 1.4–19.2 kW under SAE J1772.