Free Industrial Engineering Calculators
Make more informed motor control and electrical equipment decisions with our free online calculators. Estimate VFD sizing, braking resistor requirements, cable selection, motor starting and circuit protection.
Practical Tools for Industrial Motor & Drive Selection
Whether you’re specifying a new inverter, checking a motor starter or planning electrical protection, our five calculators provide a useful starting point for preliminary selection.
Choose Your Engineering Calculator
Select the tool for your application. Each calculator opens on its own page, where you can enter the relevant values and review the calculated recommendations.
VFD Sizing Calculator
Estimate an appropriate variable frequency drive size using motor power, voltage and application duty.
- Motor power in kW
- Motor voltage and supply configuration
- Load type and application duty
Braking Resistor Calculator
Estimate braking resistor resistance and power requirements for compatible inverter braking applications.
- Braking resistor resistance
- Approximate power requirements
- Dynamic braking duty considerations
VFD Cable Sizing Calculator
Estimate suitable motor cable dimensions for an inverter installation using electrical and installation details.
- Motor and drive current
- Cable length
- Installation considerations
Motor Starter Selection Calculator
Compare common motor starting approaches and identify a suitable starting method for your motor application.
- Direct-on-line starting
- Star-delta starting
- Soft starter selection
Fuse & Circuit Breaker Selector
Explore suitable fuse and circuit breaker options for electric motors and inverter-driven systems.
- Motor circuit protection
- VFD input protection
- Fuse and breaker selection
Use the Tools Together for a Drive Installation
Planning a variable-speed motor installation? These calculators can help you work through the main preliminary selection stages.
Size the VFD
Begin with your motor rating, voltage, rated current and application requirements.
Size Your Drive →Assess the Cable
Review the inverter-to-motor cable requirements and installation conditions.
Size Your Cable →Check Braking
If dynamic braking is needed, examine the resistor requirements and drive compatibility.
Check Braking →Select Protection
Review protective devices using the relevant current, fault and manufacturer requirements.
Select Protection →What Information Should You Have Ready?
Accurate input information makes the preliminary calculation more useful. Before starting, collect the relevant motor and installation specifications.
- Motor rated power in kW or HP
- Motor nameplate voltage and current
- Supply phase and voltage
- Application and load characteristics
- Starting, stopping and braking duty
- Cable length and installation method
- Manufacturer documentation where available
Not Sure Which Equipment You Need?
Our team can help with industrial drive selection, part-number identification, availability enquiries and potential replacement options.
Send us your motor nameplate information, application details or existing manufacturer part number.
Frequently Asked Questions
Are the engineering calculators free to use?
Can I use the VFD sizing calculator to select an inverter?
Why is motor current important when selecting a VFD?
Can I use a standard cable sizing result for every VFD?
Does every inverter need a braking resistor?
Can these calculators replace professional electrical design?
Calculated Your Requirements? Let’s Find the Right Equipment.
Once you’ve estimated your drive, cable, braking or protection requirements, our team can help you source suitable industrial equipment. Send us your specifications or existing part number for pricing and availability.