Continuous Load Minimum Circuit
Calculate continuous load minimum circuit with clear inputs, formula guidance, and practical result checks.
Continuous Load Minimum Circuit measurements
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Result
How to calculate continuous load minimum circuit
This calculator finds the minimum circuit capacity required for a continuous load, applying the standard code-required safety margin for loads running 3 hours or more.
How the calculation works
Minimum circuit capacity = Continuous load ÷ 0.8. Dividing by 0.8 (80%) finds the circuit size needed so the continuous load doesn't exceed 80% of the circuit's rating, per common code requirements.
Example
A 16A continuous load: Minimum circuit capacity = 16 ÷ 0.8 = 20A, meaning a 20A circuit is the minimum size needed.
Frequently asked questions
What counts as a continuous load?
Electrical code generally defines a continuous load as one expected to run at maximum current for 3 hours or more. Common examples include lighting circuits, some HVAC equipment, and certain fixed appliances — check your specific code definition and application.
Continuous Load Minimum Circuit
Minimum circuit capacity = Continuous load ÷ 0.8. Dividing by 0.8 (80%) finds the circuit size needed so the continuous load doesn't exceed 80% of the circuit's rating, per common code requirements.
Let's understand your continuous load minimum circuit result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Continuous Load Minimum Circuit
- This 80% rule applies specifically to continuous loads (running 3+ hours) — non-continuous loads don't require this same derating.
- Always round up to the next standard breaker size after this calculation, since breakers come in standard increments, not arbitrary amp ratings.
Common Continuous Load Minimum Circuit Mistakes to Avoid
- Applying the continuous-load derating to a load that isn't actually continuous, which would unnecessarily oversize the circuit.
When to Use This Calculator
This calculator finds the minimum circuit capacity required for a continuous load, applying the standard code-required safety margin for loads running 3 hours or more.