Breaker Sizing Calculator

This calculator helps estimate a practical breaker rating from expected load current with a safety margin.

It is useful during early panel design, budget estimation, and pre-installation discussions.

Main inputs are load current (A) and safety margin (%). Load data usually comes from nameplates, engineering schedules, or field measurements.

The tool does not pull live telemetry; output quality depends on the validity of user-entered technical values.

The calculator computes design current first: design_current = load_current x (1 + margin/100).

Then it maps the result to the first standard breaker rating that is equal to or above the design current.

Output combines design current and recommended standard breaker value, so users can see both the engineering basis and practical selection.

If design current exceeds the available list, results indicate that a different protection class or design review is needed.

Example: with 18 A load and 25% margin, design current becomes 22.5 A.

The next standard step above 22.5 A is 25 A, so the suggested breaker is 25 A, pending cable and protection coordination checks.

The tool reduces manual table scanning and provides a shared baseline across engineering and operations teams.

For electrical safety, never treat this output as final design approval. Confirm with official standards and a licensed electrician or engineer.