Amps ↔ kVA Calculator - Calculator Academy

Choose the value to solve for, select single-phase or balanced three-phase, and enter the two known RMS quantities with their units. For three-phase, use line current and line-to-line voltage.

kVA from Amps Formula

The formula below applies to single-phase apparent power. For balanced three-phase power, multiply it by √3.

kVA = I \times V / 1000

Variables:

kVA is the kVA from Amps ((kilo-volt-amps))
I is RMS current (amps); for three-phase, use line current.
V is RMS voltage (volts); for three-phase, use line-to-line voltage.

For single-phase, multiply RMS current by RMS voltage and divide by 1000. For balanced three-phase, kVA = √3 × line current × line-to-line voltage / 1000. kVA is apparent power; power factor is needed to determine real power in kW.

Amps to kVA Conversion Table (Single‑phase, common voltages)
Amperes (A)	Volts (V)	Apparent Power (kVA)
1	120	0.120
2	120	0.240
3	120	0.360
5	120	0.600
7.5	120	0.900
10	120	1.200
12	120	1.440
15	120	1.800
20	120	2.400
30	120	3.600
1	240	0.240
2	240	0.480
5	240	1.200
10	240	2.400
15	240	3.600
20	240	4.800
30	240	7.200
40	240	9.600
50	240	12.000
60	240	14.400
Single‑phase formula: kVA = (V × A) ÷ 1000. Examples above use common voltages (120 V and 240 V). For other voltages, adjust V accordingly.

How to Calculate kVA from Amps?

The following steps outline how to calculate the kVA from Amps.

First, determine RMS current (line current for three-phase).
Next, determine RMS voltage (line-to-line for three-phase).
Use kVA = I * V / 1000 for single-phase, or multiply by √3 for balanced three-phase.
Finally, calculate the kVA from Amps.
After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem :

Use these single-phase RMS values as an example problem.

total current (amps) = 30

total voltage (volts) = 20

kVA = 30 * 20 / 1000 = 0.6 kVA