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Voltage Drop Calculator

Calculate voltage drop, percentage drop, power loss & recommend cable upsize — single phase & three phase per IEC 60364

Single Phase

Three Phase

IEC 60364

Cable Table

Power Loss

Upsize Check

IEC 60364

Voltage Drop Input

System Type

⎯ Single Phase

⎯⎯⎯ Three Phase

Circuit Parameters

Supply Voltage V 230 V (1-ph) 415 V (3-ph) 400 V (3-ph) 110 V 11 kV

Current A

Cable Length m

Power Factor

Cable Selection

Cable Size Manual entry 1.5 mm² 2.5 mm² 4 mm² 6 mm² 10 mm² 16 mm² 25 mm² 35 mm² 50 mm² 70 mm² 95 mm² 120 mm²

R per km Ω/km

VD Limit % 3% IEC standard 5% max allowed 2% critical 1% sensitive

Reactance X Ω/km

Drop Analysis

Calculation Results

SRC
—V

LOAD
—V

Source ▼ — V drop At Load

Voltage Drop %—

0%3% limit10%

Voltage Drop

—

Volts

Cable Size Comparison

Size mm²	R Ω/km	Ampacity A	VD Volts	VD %	Status

► Formulas

Voltage Drop (IEC 60364)

1-Phase: VD = 2 × I × L × (R·cosφ + X·sinφ)/1000

3-Phase: VD = √3 × I × L × (R·cosφ + X·sinφ)/1000

VD% = (VD / V_supply) × 100

P_loss = I² × R_total (Watts)

Limit: 3% IEC · 5% max · 2% critical

⚠ Note: Calculations at 20°C. At operating temperature (70°C PVC), multiply R by ~1.28. Verify against IEC 60364-5-52 and local wiring regulations.

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