Electrical & Drives
Motor Full-Load Current Calculator
Estimate motor full-load current from shaft output or electrical input without applying efficiency twice.
This tool provides a preliminary engineering calculation for reference. Final equipment selection, design and commissioning decisions must consider manufacturer data, applicable standards, operating conditions and project-specific engineering requirements. It is not certified design output.
Preliminary result
Calculated outputs
Enter values and select Calculate. Results are estimates and do not replace nameplate data, applicable standards, or an engineering review.
Use this calculation
Only calculator parameters and results are transferred. Personal details are collected separately in the destination form.
Formula
Three phase: I = Pin × 1000 / (√3 × V × PF)
Single phase: I = Pin × 1000 / (V × PF)
For shaft output only: Pin = Pout / η
Worked example
15 kW shaft-output motor, 415 V, PF 0.85 and 90% efficiency.
Expected check: Estimated full-load current = 27.28.
Assumptions
- • Balanced sinusoidal supply
- • Entered voltage is RMS line voltage
- • Efficiency and power factor apply at the stated operating point
Limitations
- • Estimate only; use the motor nameplate and applicable standard for final design
- • Does not determine protection, cable size, starting method or acceleration current
Frequently asked questions
Can this result be used for final equipment selection?
No. Use it for a preliminary check, then verify manufacturer data, site conditions, applicable standards and the complete system design.
What does formula version 1.0.0 mean?
It identifies the exact calculation logic used so a saved result can be traced when the formula register changes.
Can Elexorn review my calculation?
Yes. Transfer the result to Request a Quote or Talk to an Elexorn Engineer and add the relevant project or equipment details.