Power Calculator (Load, Equipment & Distribution Planning)
Power calculator workflows for factory load, diversity factors, transformer and generator sizing, and distribution planning—for plant expansion, workshop retrofit, and utility planning.
This hub is the primary entry for the Power Systems cluster. Start from facility demand, then follow cross-cluster tools for transformer and generator sizing, distribution guides, and power factor correction. For kW-kVA conversion, breaker, and cable checks, use the partner Electrical Calculator hub.
What is a Power Calculator?
A power calculator helps engineers estimate facility demand, apply diversity and demand factors, plan distribution and power quality improvements, and select practical transformer and generator ratings. It connects load definition to equipment sizing and downstream protection checks.
Common Power System Calculations
- Roll up connected load and estimate demand for a facility.
- Apply diversity and demand factors before transformer sizing.
- Size transformer and generator from target kVA demand.
- Plan panel schedules, load balance, and PF correction.
- Review harmonics and unbalanced 3-phase impacts on sizing.
Start Here
Factory Load Calculator
Most power-system workflows start from real load definition before conversion, protection, or equipment sizing.
Use Factory Load Calculator →Tool List & Guides by Topic
Facility Load
Define connected equipment and estimate facility kW, kVA, and line current.
Factory Load Calculator
Estimate total facility demand from equipment inventory and operating assumptions.
Use Calculator →Load planning guides
Generator
Size standby or prime generator capacity from load and power factor; plan UPS bridge for transfer.
Generator + UPS Calculator
Size generator kVA and plan UPS bridge minutes for ATS transfer.
Use Calculator →Generator workflow: Factory Load → Generator Size → Fuel & Runtime Planning → Generator + UPS → ATS Transfer Guide · UPS Calculator hub.
Feeder checks: Breaker Size · Cable Size · Motor Starting Guide.
Transformer
Select transformer kVA from demand profile; review loss, derating, and the 80% planning rule in guides.
Transformer Size Calculator
Select practical transformer rating from target kVA demand.
Use Calculator →Transformer guides
- Factory Load vs Transformer Size
- Transformer Sizing Guide
- Transformer Efficiency & Loss
- Transformer Derating Factors — includes 80% loading rule context
- Transformer Impedance (%Z) — fault planning context
- Voltage Regulation Explained
- Transformer Sizing for Harmonic Loads
- How to Calculate Transformer Size
After kVA screening: line amps via kVA to Amps · fault/coordination via Short-Circuit and Coordination guides.
Distribution
Plan panel schedules, load balance, and feeder protection handoff to the Electrical hub.
- Electrical Distribution System Design — panel and feeder planning
- How to Design Electrical Panels — panel schedule and layout
- Unbalanced Load in 3-Phase Systems — load balance impact
- Short-Circuit & Fault Current Planning — SCCR checklist (not a fault calculator)
After demand is defined, continue protection and cable checks on the Electrical Calculator hub: Breaker Size, Cable Size, Voltage Drop.
Power Quality
Screen power factor correction, harmonics, and THD before capacitor bank design.
kW to kVAR Calculator
Calculate reactive power from kW and PF—first step in correction planning.
Use Calculator →Power quality guides
Electrical Conversion & Cable (Partner Hub)
kW-kVA conversion, 3-phase power, breaker, and cable tools live on the Electrical hub—use them after load is defined on this page.
Power Systems Path Map
Goal → start here. All paths assume load is defined first unless noted.
| Goal | Path |
|---|---|
| Roll up facility kW | Factory Load |
| Connected vs demand vs load factor | Connected vs Demand → Diversity → Load Factor |
| Size transformer | Factory Load → kW to kVA → Transformer Size · Guide |
| Size generator | Factory Load → Generator Size |
| Generator + UPS transfer | Generator + UPS · ATS Guide · UPS Hub |
| PF correction & harmonics | kW to kVAR → Capacitor Bank → Harmonics |
| Panel / distribution plan | Distribution Design → Panel Design |
| Fault / SCCR planning | Fault Planning → Coordination |
| Breaker, cable, voltage drop | Electrical Hub (after kVA/amps from load) |
Calculation Workflow
- Full facility path: Factory Load → Connected vs Demand → Diversity Factor → kW to kVA → Transformer Size → Breaker Size → Cable Size.
- Backup power path: Factory Load → Generator Size → Generator + UPS → UPS Calculator hub.
- PF correction path: Factory Load → kW to kVAR → Capacitor Bank Guide → Harmonics Guide.
- Distribution + protection: Distribution Design → Fault Planning Overview → Electrical hub for breaker, cable, and voltage drop.
- Energy & load factor review: Meter peak vs average → Load Factor Guide → Energy Estimator.
Use Cases
- Plant expansion: roll up new equipment demand before transformer procurement.
- Workshop retrofit: validate diversity and PF after machine replacement.
- Backup strategy: compare generator and UPS sizing for critical loads.
Which Power Calculator Should You Use?
| Goal | Recommended Tool or Guide |
|---|---|
| Estimate plant / facility demand | Factory Load Calculator |
| Understand connected vs demand load | Connected vs Demand Load Guide |
| Apply diversity factor | Diversity Factor Guide |
| Calculate load factor (peak vs average) | Load Factor Guide |
| Size transformer from demand | Transformer Size Calculator |
| Review transformer loss and 80% rule | Transformer Loss Guide |
| Understand transformer %Z for faults | Impedance (%Z) Guide |
| Size generator from load | Generator Size Calculator |
| Plan generator fuel / runtime (screening) | Fuel & Runtime Guide |
| Plan generator + UPS transfer | Generator + UPS Calculator |
| Plan panel schedule and feeders | Distribution Design Guide |
| Plan fault current / SCCR checklist | Fault Planning Overview |
| Screen power factor correction | kW to kVAR + Capacitor Bank Guide |
| Review harmonics / THD risk | Harmonics Guide |
| Convert kW to kVA or size cable | Electrical Calculator hub |
Related Guides
Partner Hub: Electrical
Conversion (kW-kVA, kVA-amps), 3-phase power, breaker sizing, cable sizing, and voltage drop are centralized on the Electrical Calculator hub. Use this Power hub for load roll-up and equipment planning; switch to Electrical for feeder and protection checks.
FAQ
What is a power calculator used for?
It estimates facility demand, applies diversity and demand factors, supports transformer and generator sizing, and links to distribution and power quality planning guides.
How to calculate kVA from factory load?
Roll up connected kW in the Factory Load Calculator, apply diversity if needed, then convert with kW / PF on the kW to kVA calculator.
What is the difference between this hub and the Electrical Calculator hub?
This hub starts from facility load and equipment sizing; the Electrical hub handles conversion, breaker, cable, and voltage drop on the same project.
Which calculator should I start with for factory expansion?
Start with Factory Load, review diversity and demand guides, then size transformer or generator and hand off to Electrical tools for feeder checks.
Where is load factor covered?
See Load Factor for Factory Demand for peak vs average kW. Use it with meter data alongside connected vs demand and diversity guides—not as a substitute for peak sizing.
How do I plan for short-circuit and fault current?
Use the Short-Circuit Planning Overview for SCCR and coordination checklists, then steady-state tools on the Electrical hub. This site does not replace bolted-fault studies.