V
Please enter all required numeric values.
RESULTS
Input Parameters Specification
Source VoltageSelect system voltage. The selected value represents allowed voltage drop used by the original calculator logic.
PhaseChoose single phase or three phase for electrical wire size and cable size calculation.
MaterialSelect copper or aluminium. Material constant K changes the required circular mil wire area.
CurrentLoad current in amperes used to size the conductor for voltage drop conditions.
DistanceOne-way cable run distance in feet for the wire gauge sizing calculation.
Wire Size OutputRecommended AWG or MCM wire size based on the original circular mil lookup table.
Practical Operational Examples
Electrical Wiring Design
Estimate copper wire size for lighting circuits, pumps, motors, panels, inverters, and branch wiring.
Long Cable Runs
Use aluminium or copper material selection to compare wire gauge for distance-based voltage drop sizing.
Diagrams & Theory
Wire size selection depends on voltage drop, conductor material, current, phase, and cable run distance. Larger current or longer distance usually requires a larger AWG or MCM conductor.
Formulas & Mathematical Logic
Step 1: Read source voltage drop value vp, phase multiplier, material constant K, distance, and current.
Step 2: Calculate circular mil area: CM = (Phase × K × Distance × Current) / Voltage Drop.
Step 3: Compare CM with the original lookup ranges L and H.
Step 4: Return matching AWG or MCM wire size from the original size table.
Step-by-Step Example
Example: select 240 V, single phase, copper, current = 30 A, and distance = 100 ft.
The calculator reads the selected voltage drop value from the voltage dropdown.
It applies the selected phase multiplier and material K constant.
Then it calculates circular mil area and finds the matching AWG/MCM size from the original lookup table.
How to Use This Calculator
Select the source voltage.
Choose single phase or three phase.
Select copper or aluminium material.
Enter current in amperes.
Enter cable distance in feet.
Click Calculate to get the recommended wire size.
About This Calculator
Estimate electrical wire size for voltage-drop based cable planning.
The CalcBoy Wire Size Calculator helps estimate AWG or MCM conductor size from voltage, phase, material, current and cable distance.
Wire size selection matters because every conductor has resistance. When current flows through a long wire, some voltage is lost before it reaches the load. If the wire is undersized, motors may run hot, pumps may start weakly, lighting may dim, and sensitive equipment may behave poorly. This calculator gives a quick planning estimate using voltage drop logic and a built-in AWG/MCM lookup table.
Copper and aluminium conductors behave differently. Copper normally needs a smaller size for the same current and distance because it has lower resistance. Aluminium can be useful for feeders and long cable runs, but the required conductor size is usually larger. This calculator lets you switch material, phase, voltage, current and distance quickly, so you can compare practical wiring options during early design.
Best UseEarly wire sizing for branch circuits, feeders, motors, pumps and inverter wiring.
Material ChoiceCopper and aluminium use different K constants in the calculation.
Distance EffectLonger runs increase required wire size because voltage drop increases.
Safety ReminderFinal conductor selection must follow local electrical code and breaker rules.
Tip: Voltage drop calculation is only one part of wire sizing. Always verify ampacity, insulation rating, conduit fill, temperature correction, grounding and local electrical code before installation.
Frequently Asked Questions
What does this wire size calculator calculate?
It estimates the required AWG or MCM wire size using voltage, phase, conductor material, current and distance.
Why does distance affect wire size?
Longer wire runs have more resistance, which increases voltage drop. A larger conductor helps reduce that voltage loss.
Why does aluminium need a larger wire size than copper?
Aluminium has higher resistance than copper, so it often needs a larger conductor for the same current and distance.
Can I use this for three phase wiring?
Yes. Select Three in the phase dropdown to use the three-phase multiplier in the original calculation logic.
Is the result enough for final installation?
No. This is a planning estimate. Final wiring must be checked against local electrical code, breaker size, insulation type and installation conditions.
What is AWG?
AWG means American Wire Gauge, a standard used for naming conductor sizes.
What is MCM?
MCM, also called kcmil, is used for larger wire sizes and means thousands of circular mils.
Related Calculators
Copper and Aluminium Wire Cable Size CalculatorCompare both conductor materials side by side.
Voltage Drop CalculatorEstimate voltage lost across a wire run.
Ohm’s Law CalculatorCalculate voltage, current, resistance and power.
SWG to MM ConverterConvert wire gauge to diameter and area.