VoltCheck24 Engineering Calculator

DC Cable Size Calculator for Battery, Solar, and Control Wiring

Estimate DC cable size for battery, solar, control panel, and low-voltage equipment wiring using current, distance, and voltage-drop limits.

Open Interactive Calculator Open DC Cable AWG and mm2 Table

How to use this calculator

Collect the values below from the equipment nameplate, data sheet, or field measurement.
Enter values using one consistent unit system and use worst-case operating conditions.
Review the result, margin, and engineering note before selecting hardware.
Cross-check the result with the related calculator and save the review for your project record.

Input checklist

Cable route length
Load current and duty cycle
Installation temperature and grouping
Fuse or breaker rating

Example field question

Use this calculator when a design review or site issue requires a quick engineering check before a detailed manufacturer selection.

Common mistakes to avoid

Do not mix nominal values with measured worst-case values. Keep units consistent and include cable, temperature, duty, and derating assumptions where applicable.

Standards and validation

Review the result against local codes, IEC/NEC/NFPA/ISO practices when applicable, project specifications, and the latest manufacturer data sheet.

Recommended workflow

Start with the primary calculation, then use the related tool to check the next design dependency. Save or print the result only after the assumptions and worst-case conditions are confirmed.

Start with the primary inputs Check the related dependency

Formula and Inputs

Cable voltage drop is calculated from conductor resistance per length, round-trip path length, and operating current.

Industrial Use Cases

Use this calculator for panel feeders, DC branch circuits, battery devices, lighting, instrumentation, and small motor loads.

Engineering Note

For final cable selection, verify short-circuit protection, terminal temperature rating, insulation type, grouping derating, and local wiring rules.

FAQ

Is cable size the same as wire size?

In search language they are often used together. Practically, cable selection also includes insulation, sheath, installation environment, and number of conductors.

Can I use this for AC cable sizing?

This page is focused on DC voltage drop. AC systems may need impedance, power factor, phase configuration, and local code checks.

Preliminary engineering reference only. Confirm final selections against current standards, project specifications, and manufacturer data.