Select the motor
Choose single-phase or three-phase, then select whether you are designing a new motor or working from an existing motor for rewind planning.
1 Type
2 Specs
3 Core
4 Stator/Rotor
5 Winding
6 Connection
7 Materials
8 Results
1. Motor Type & Mode
2. Motor Requirements
kW
Enter motor nameplate power
Synchronous RPM will be calculated
Design target only; final efficiency requires standardized loss/efficiency testing.
Typical: 0.75–0.92
3. Mechanical / Core Dimensions
Usually close to stator bore
4. Stator & Rotor Design
Recommended: 0.3–1.5 mm
ⓘ Rotor/Stator Slot Compatibility: For 36 stator slots and 28 rotor slots, the combination is acceptable.
5. Winding Design
Full-pitch = slots/pole
Typical: 4–7 A/mm²
Typical: 60–75%
Design input used to calculate flux per pole and turns
Use lamination supplier data at your operating B and frequency
Calculator also derives a geometry-based Kw for validation
6. Connection & Starting
Based on winding voltage vs. supply voltage
For star: V_phase = V_line/√3; for delta: V_phase = V_line
Typical: 30–40% of DOL
Star / Delta Connection Reference (IEC terminal designations)
Important: Star-delta starting is applicable only when the motor is intended to run in delta at the supply line voltage and all six winding ends are accessible. In star starting, each winding receives VL/√3 and starting torque is approximately one-third of direct-delta torque.
7. Materials & Mass Production
8. Results & Validation
Enter all parameters and click Calculate Motor Design.
The dashboard will populate with electrical, winding, material, and cost estimates.
How to Use This Tool
4 simple stagesMove through the design steps in order. The calculator keeps your inputs while you progress, then combines them into one engineering result at the final stage.
Enter design data
Provide power, voltage, frequency, poles, RPM, efficiency, power factor, duty, insulation, core, stator, rotor and winding parameters.
Set winding & connection
Configure conductor, current density, fill target, coil pitch and connection details. Use the star/delta and single-phase options where applicable.
Calculate & review
Open Results and calculate the design. Review electrical performance, winding schedule, connection diagram, material quantities, BOM and nameplate data.
Tip: For a rewind job, enter measurements and nameplate values from the original motor as accurately as possible. Estimated outputs should be verified before manufacturing or rewinding.
What You Can Do With This Tool
Design · Rewind · EstimateUse the calculator as a structured motor-design worksheet for early engineering, workshop planning, rewinding reference and production estimation.
Estimate electrical performance
Calculate current, synchronous speed, slip, torque, input power and other key operating values from your selected specifications.
Plan stator & rotor geometry
Work with core dimensions, slot counts, air gap, shaft, rotor and lamination parameters in one design flow.
Build a winding reference
Estimate turns, conductor requirements and generate a winding schedule to support winding and rewind planning.
Review motor connections
Visualize applicable star/delta or single-phase connection information and check the selected connection against the design.
Estimate materials & BOM
Review approximate copper, steel, rotor material, insulation, frame and related quantities for one motor or a production batch.
Support production planning
Use quantity, material cost, labor, overhead and scrap assumptions to create an early production and costing estimate.
Engineering note: This calculator is intended for preliminary design and estimation. Final motor manufacture should be validated against electromagnetic, thermal, mechanical, insulation, safety and applicable IEC/NEMA requirements.
Interpretation
Use the calculated values as preliminary engineering estimates. Synchronous speed is determined by supply frequency and pole count, while actual rotor speed is lower under normal motoring operation and the difference is represented by slip. Rated torque represents approximate shaft torque at the entered output power and speed. Winding, conductor, magnetic, loss, temperature and material results should be evaluated together rather than independently. Final manufacturing or rewinding decisions require verification against the actual lamination geometry, winding data, insulation system, motor nameplate, thermal limits and prototype/test results.
Variables
| Symbol | Quantity | Unit |
|---|---|---|
| Ns | Synchronous Speed | rpm |
| f | Supply Frequency | Hz |
| P | Number of Poles | poles |
| Nr | Rated Rotor Speed | rpm |
| s | Slip | % |
| T | Rated Shaft Torque | N·m |
| Φ | Flux per Pole | Wb |
| Tφ | Turns per Phase | turns |
| Kw | Winding Factor | dimensionless |
| I | Rated Current | A |
Common mistakes
Confusing line voltage with phase voltage; using Star/Delta connections without checking the motor nameplate voltage; entering rotor speed above synchronous speed; treating preliminary efficiency estimates as tested efficiency; using incorrect stator or rotor dimensions; ignoring winding factor and slot fill; selecting an unsuitable current density; and using preliminary winding or BOM results for production without prototype validation.Applications
Use this calculator for preliminary induction motor design, motor winding study, rewinding reference, synchronous-speed and slip calculations, rated-current estimation, shaft-torque calculations, conductor sizing, winding-turn estimation, Star/Delta connection study, stator and rotor geometry evaluation, material estimation, BOM planning, and educational analysis of single-phase and three-phase induction motors.Related calculators · Electric Machines
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