Motor Current Calculator

Calculate Full Load Current for Single-Phase & Three-Phase Motors

⚡ Motor Power (kW)

🔌 Voltage (V)

📈 Efficiency (%)

📊 Power Factor (PF)

🔗 Motor Type

📌 Unit

💡 Formulas: Single Phase: I = P / (V × PF × η) | Three Phase: I = P / (√3 × V × PF × η)

I = P / (V × PF × η) (Single) | I = P / (√3 × V × PF × η) (Three)

📖 Motor Current Calculator

This tool calculates the full load current (FLC) for single-phase and three-phase induction motors. Proper current calculation is essential for selecting the correct circuit breaker, cable size, and motor protection devices.

📐 Motor Current Formulas

Single Phase: I = P / (V × PF × η)
Three Phase: I = P / (√3 × V × PF × η)
Starting Current: I_start = 5 to 7 × I_FLC

📊 Typical Motor Parameters

Power (kW)	3-Phase Current @415V	PF	Eff%	Starting (A)
0.75	1.5	0.75	80	7.5
1.5	2.8	0.78	82	14
2.2	4.0	0.80	83	20
3.7	6.5	0.82	85	33
5.5	9.5	0.83	87	48
7.5	13.0	0.85	88	65
11	18.5	0.86	89	93
15	25.0	0.87	90	125
22	36.0	0.88	91	180
37	60.0	0.89	92	300
55	88.0	0.90	93	440
75	120.0	0.90	93	600

📌 Motor Starting Current

Direct On Line (DOL): 5-7 × FLC
Star-Delta: 1.5-2.5 × FLC
Soft Starter: 2-4 × FLC
VFD: 1-1.5 × FLC

❓ Frequently Asked Questions

How to calculate motor full load current? ▼

Three phase: I = P / (√3 × V × PF × η). Single phase: I = P / (V × PF × η).

What is motor starting current? ▼

Starting current is 5-7 times FLC for DOL starting.

How to convert HP to kW? ▼

1 HP = 0.746 kW. Multiply HP by 0.746.

What is typical power factor for motors? ▼

Small: 0.75-0.80. Medium: 0.80-0.85. Large: 0.85-0.90.