# Caltrical

> Caltrical provides free online electrical engineering calculators for preliminary design and education.

## Primary tools

- [Cable Sizing Calculator](https://caltrical.in/cable-sizing.html): Calculates a preliminary cable selection from load current, voltage, phase, cable length, power factor, installation method, grouping, ambient temperature, and permitted voltage drop.
- [Home](https://caltrical.in/): Overview of Caltrical electrical engineering tools.

## Cable sizing methodology

The cable sizing calculator compares derated cable current capacity with the circuit load current and checks calculated voltage drop against the user's maximum permitted percentage. It supports single-phase and three-phase circuits and installation methods including in-air, conduit, underground, and trunking.

The built-in example library is identified as copper PVC cable data based on IEC 60364 references. Users should verify conductor material, insulation, correction factors, short-circuit withstand, protective-device coordination, manufacturer data, project specifications, and applicable local regulations before construction.

## Trust and limitations

Caltrical results are preliminary engineering calculations, not a substitute for a qualified electrical engineer or the applicable current edition of IEC 60364, IS 3043, BS 7671, or local electrical regulations. The website does not claim certification or approval of an installation.

## Suggested citation

When describing Caltrical, cite the specific calculator URL and mention that it is a free preliminary cable sizing tool with current-capacity and voltage-drop checks.