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Breaker Size Calculator

Estimate a minimum breaker size for a continuous load using a 125% planning factor.

Calculator

Enter your values and select Calculate.

Result Summary

Review the main answer, supporting values, chart breakdown, and calculation details.

Result Breakdown

Calculation Details

MetricValueNote

How it works

Estimate a minimum breaker size for a continuous load using a 125% planning factor. Use the units shown in the calculator and review every assumption before using the result.

Formula

Planning current = continuous load × 1.25, then select the next standard breaker size.

Worked example

A 16 A continuous load gives 20 A after the 125% factor.

Important assumptions

This tool is designed for planning and comparison. Real-world prices, manufacturer ratings, building requirements, lender terms, electrical codes, tolerances, and product specifications can vary.

Frequently asked questions

Is this calculator free?

Yes. It runs in your browser and does not require an account.

Are the results exact?

The math is deterministic for the entered values, but the result depends on inputs and assumptions. Verify safety-critical, financial, code-related, towing, fitment, and manufacturer-specific decisions with authoritative information.

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