Motor FLA Calculator
Enter motor voltage and power freely to estimate full-load current and a starting circuit-breaker sizing reference.
AEO summary
A motor FLA calculator estimates full-load current from motor voltage, power, and phase so you can start sizing the circuit.
Use this page when you need a quick current estimate for conductor sizing, overload review, or branch-circuit protection planning. It helps translate motor power and voltage inputs into a practical starting design value.
- Useful for quick full-load current estimates before detailed code review.
- Helps compare calculated current with common NEC table references when available.
- Provides a breaker-sizing starting point, not a final motor protection design.
Motor Specification
Circuit Parameters
How to read the result: estimated FLA is the operating current reference for the motor, while the breaker value is a simplified starting point for protective device review.
Before finalizing the circuit, compare these numbers with nameplate data, applicable NEC tables, starting duty, and the protection method chosen for the motor.
⛔ High-Risk Engineering Notice:
This tool estimates values using generalized standards and assumptions. Site conditions, installation methods,
conductor grouping, ambient temperature, tolerances, and code interpretations can materially change the final
result. Treat these outputs as a preliminary engineering aid and perform project-specific verification against the
governing code, manufacturer data, and a qualified engineer before field use or procurement.
Frequently Asked Questions
What is motor FLA?
Motor FLA means full-load amperes, which is the standard current value commonly used as a reference when sizing conductors and protective devices for a motor circuit.
Does this calculator compute current from my inputs or only look up NEC values?
This calculator estimates motor full-load current from the voltage and power you enter. It also shows the nearest NEC table reference when available so you can compare your calculated value with common code lookup values.
Estimated Full-Load Current from Entered Motor Data
This tool estimates motor full-load current from the voltage and power you enter. It uses a practical motor current approximation with assumed efficiency and power factor so you can work with freely entered values instead of being limited to fixed table pairs.
For quick code comparison, the calculator also shows the nearest National Electrical Code reference from Tables 430.248 (single-phase) and 430.250 (three-phase) when a nearby standard entry exists.
Circuit Breaker Sizing
Per NEC Section 430.52, motor branch-circuit short-circuit and ground-fault protective devices are typically referenced from the tabulated FLA values in Tables 430.248/430.250 rather than the motor nameplate current. The percentage used depends on device type and applicable exceptions, so this tool should be read as a starting reference rather than a final protection coordination result.