Electrical Load Calculator
A professional tool for collecting and calculating electrical loads in residential and commercial buildings. The calculator sums up the installed power of all loads, applies demand and coincidence factors per international standards, and computes the design current.
Supports per-phase load distribution for three-phase networks — you can see the current on each phase, identify imbalance, and adjust the distribution of electrical loads accordingly.
Features
- Floor-by-floor and room-by-room load collection
- Installed and design power calculation (kW/kVA)
- Demand factor (Kd) and coincidence factor (Kc) application
- Per-phase current calculation (L1, L2, L3)
- Phase imbalance detection
- Load schedule export to PDF/Excel
- Power supply reliability category determination
Standards
- IEC 60364 — Low-voltage electrical installations
- SP 256.1325800 — Electrical equipment of residential and public buildings
- IS 732 — Indian standard for electrical wiring installations
Frequently asked questions
What is the demand factor Kc?
Kc is the ratio of calculated to installed power — not all devices run at once. For a single dwelling Kc = 1.0, for groups of apartments 0.5–0.9 (SP 256.1325800 / IEC).
When do I need 3-phase?
When the calculated load exceeds 10 kW. Phase current drops by √3: 12 kW = 17.3 A per phase at 400 V.
Why Kc = 1 for one apartment?
All installed devices in a single dwelling can run simultaneously, so the calculated load equals the installed one.
How to calculate the main current?
I = P/(√3·U·cosφ) for 3-phase, I = P/(U·cosφ) for 1-phase. 10 kW at 230 V ≈ 43 A — you need a 40–50 A supply.