DC Wire & Cable Sizing Calculators

Engineered tools for calculating conductor gauge (AWG and metric mm²), circuit loop resistance, and voltage drop across 12V, 24V, 36V, and 48V DC systems.

Core Sizer

DC Conductor Sizing & Voltage Drop Calculator

Dual-constraint solver determining the exact AWG and mm² conductor needed to satisfy both voltage drop percentage and ABYC Table 6B ampacity limits.

Analysis

Exact DC Voltage Drop Calculator

Analyzes known conductor sizes, determining exact loop resistance, operating voltage at the load, and energy dissipated as heat in watts.

High Amp

Inverter DC Cable Sizing Tool

Sizes primary battery-to-inverter cables accounting for low-voltage cutoff current spikes and terminal lug specs.

Marine

Trolling Motor Cable & Breaker Sizer

Calculates wire gauge and manual-reset thermal circuit breakers for 12V, 24V, and 36V bow and transom trolling motors.

Vehicle

DC-to-DC Charger Cable Sizer

Determines wire sizes for both the input alternator circuit and output auxiliary battery circuit for vehicle chargers.

Solar

Solar Array to MPPT Cable Sizer

Minimizes transmission power losses on rooftop PV strings running to charge controllers.

Battery

Battery Interconnect Cable Sizer

Selects jumper cables and terminal lug dimensions for series and parallel battery banks to maintain balanced cell resistance.

Automotive

Alternator Primary Cable Sizer

Sizes charging cables between the alternator B+ terminal and battery with engine bay ambient temperature derating.

Comparison

Chassis Ground vs Dedicated Return Comparison

Evaluates resistance, voltage drop, and electrical noise differences between vehicle chassis grounding and dedicated copper returns.

Lighting

LED Strip Voltage Drop Sizer

Calculates end-of-run voltage sag on 12V and 24V LED tape lighting to prevent visible color shifts and determine power injection intervals.

Conductor Sizing Standards

Calculated voltage drop uses nominal uncoated-copper conductor resistance at 75°C (167°F), based on NEC Chapter 9, Table 8. The ampacity reference uses ABYC E-11 Table 6B assumptions. Actual installations can differ because of conductor construction, operating temperature, installation conditions, terminations, equipment requirements, and applicable standards.

This calculator provides an educational sizing reference. It is not system-specific engineering certification, code-compliance determination, or a guarantee of installation safety.