Inputs
Enter loads, factors, and supply details.
Example Data Table
| Equipment | Qty | Unit (W) | Duty (%) | Item DF | Estimated Item Demand (W) |
|---|---|---|---|---|---|
| Tower crane | 1 | 55000 | 60 | 0.80 | 26400 |
| Welding sets | 6 | 9000 | 40 | 0.70 | 15120 |
| Lighting & small power | 1 | 18000 | 100 | 0.90 | 16200 |
| Connected (sum) | 57720 | ||||
Formula Used
1) Connected Load
Connected (kW) = Σ[ Qty × Unit(W) × (Duty%/100) × ItemDF ] / 1000
2) Apply simultaneity
Base (kW) = Connected(kW) × Diversity × Coincidence
3) Losses + efficiency
kW' = Base × (1 + Losses%/100) × (100 / Efficiency%)
4) Add margins
Demand (kW) = kW' × (1 + Expansion%/100) × (1 + Safety%/100)
5) Convert to kVA and Current
kVA = kW / PF
3φ A = (kVA×1000)/(√3×V) · 1φ A = (kVA×1000)/V
How to Use This Calculator
- Pick an estimation mode: equipment list or area density.
- Enter supply details (phase, voltage) and power factor.
- Add equipment rows with realistic duty and item factors.
- Set diversity and coincidence for peak overlap behavior.
- Add losses, efficiency, expansion, and safety margin.
- Press Estimate Demand to view results above.
- Use CSV/PDF buttons to export saved history.
Tip: Start conservative, then refine as schedules finalize.
Saved Calculation History
Your last 100 estimates are kept in this browser session.
| Time | Project | Connected (kW) | Demand (kW) | kVA | A | V | Φ | PF |
|---|---|---|---|---|---|---|---|---|
| No saved results yet. Run an estimate to populate this table. | ||||||||
Disclaimer
This tool provides planning-level estimates only. Always confirm with detailed load schedules, manufacturer data, diversity studies, and your local electrical code requirements before procurement or installation.