Motor HP, Current & Cable Size Calculator | IEEE / IEC Standards

⚡ Motor Engineering Tools

Professional Motor Calculators

HP · Full Load Current · Cable Sizing — Per IEC, IEEE & BS 7671 Standards

IEC 60364 BS 7671 IEEE Std 3Φ / 1Φ Derating Factors Voltage Drop

🔧 Motor Horsepower (HP) Calculator

Calculate motor output power from voltage, current, PF and efficiency

Phase Configuration

Supply Phase

System Voltage (V) 400 V (3Φ Standard) 415 V (3Φ Legacy) 230 V (1Φ) 220 V (1Φ Legacy) Custom...

Electrical Parameters

Current (A)

Motor nameplate current

Power Factor (cos φ)

Typical range: 0.70 – 0.95

Efficiency (%)

Typical range: 80% – 96%

Results

Output Power

—

HP (Horsepower)

—

Output Power

—

kW (Kilowatt)

Input Power

—

kW

—

Apparent Power

—

kVA

Reactive Power

—

kVAr

Power Loss

—

kW (as heat)

—

📋 Motor Power Reference Table

HP	kW	3Φ 400V FLC (A)	Common Application
0.5 HP	0.37 kW	1.0	Small pump, fan
1 HP	0.75 kW	1.9	Cooling pump
2 HP	1.5 kW	3.7	Conveyor, mixer
5 HP	3.73 kW	8.5	Compressor, pump
10 HP	7.46 kW	16	Industrial pump
20 HP	14.9 kW	30	Large compressor
50 HP	37.3 kW	67	Industrial machinery
100 HP	74.6 kW	133	Large industrial motor

*FLC based on PF=0.85, η=90%, 400V three-phase

⚡ Motor Full Load Current (FLC) Calculator

Calculate full load current from rated power — essential for circuit protection design

Phase & Supply

Supply Phase

System Voltage (V) 400 V (3Φ Standard) 415 V 230 V (1Φ) 220 V Custom...

Motor Power

Motor Power

kW HP kVA

10 kW = 13.4 HP = 11.76 kVA (per PF=0.85)

Motor Type IE1 (Standard) IE2 (High Eff) IE3 (Premium) IE4 (Super Prem)

Power Factor (cos φ)

IE2 Motor: 0.85–0.90

Efficiency (%)

IE2 Motor: 88–93%

Additional Parameters

Starting Method DOL (Direct On Line) Star-Delta Soft Starter VFD

Starting Multiplier

DOL: 5–8x FLC (typical)

Quantity

Number of identical motors running

Current Results

Full Load Current

—

A (per motor)

Starting Current

—

A (peak)

—

Total Current (×qty)

—

A

Input Power

—

kW

Apparent Power

—

kVA

Recommended Breaker

—

A (FLC × 1.25)

Starting Method Comparison

—

🔌 Motor Cable Size Calculator

Per IEC 60364-5-52 & BS 7671 — with derating factors & voltage drop

Load Information

Full Load Current (A)

Take value from FLC Calculator above

System Voltage (V) 400 V (3Φ) 415 V 230 V (1Φ) Custom...

Cable Length (m)

From motor to panel/MCC

Cable Specification

Conductor Material

Installation Method In Conduit (Ka=0.80) Cable Tray (Ka=1.00) Clipped Direct (Ka=1.00) Buried Underground (Ka=0.90) In Free Air (Ka=0.95)

Ambient Temperature (°C)

Typical tropical: 35–45°C

Grouping Factor (Kg) 1 cable — 1.00 2–3 cables — 0.80 4–6 cables — 0.70 7–9 cables — 0.65 10+ cables — 0.60

Safety Margin (%)

IEC Standard: 25% (1.25× FLC)

Results

Recommended Cable Size

—

mm²

Cable Ampacity

—

A (table rating)

Derated Ampacity

—

A (after derating)

Voltage Drop

—

V

—

Voltage Drop %

—

% (limit: 5%)

Derating Factor

—

Kt × Kg × Ka

Derating Breakdown

Standard Cable Size Comparison

—

⚠️ Engineering Disclaimer: These calculators are for estimation and educational purposes only. Always verify results against motor nameplate data, manufacturer specifications, and applicable local electrical codes (IEC, BS 7671, NEC). Have a qualified electrical engineer review all final designs.