Electrical Load Calculator (Commercial)

Commercial buildings are sized load by load: the lights that run all hours in an office, the ovens and fryers that stack at lunch in a restaurant, the chiller that drags demand up on the hottest afternoons. Unlike a home, every group has its own schedule and its own diversity, so the honest answer needs groups, not a single number.

Electrical Load Calculator (Commercial) separates lighting (by density presets per square metre), power outlets, HVAC, and dedicated equipment groups — each with a connected load and its own demand factor. A building-level diversity factor then combines group demands into the diversified total, kVA and a suggested service class, with the maths visible at every step.

It is a first-pass planning figure for the utility application, the main panel and the consultant to refine. Everything runs in the browser; nothing is uploaded.

• Grouped commercial model: Lighting, power outlets, HVAC and dedicated equipment each with independent demand factors.
• Lighting density presets: Watts per m² for offices, shops, restaurants, warehouses and showrooms.
• Operating schedules: A per-group hours-per-day input scales equipment that runs short shifts.
• Building diversity: Combine group demands under a single diversity multiplier.
• Ultimate totals: Connected kW, diversified demand, kVA and a suggested service class.
• Live maths: Every group interconnection shown line by line.
• Export: Copy or download the demand report as text, CSV or JSON.
• Learning guide: Demand vs diversity, lighting densities and schedule logic.

1. Set the supply. Choose single-phase or three-phase and the voltage.
2. Enter the floor area in square metres; lighting density presets apply if you pick one.
3. Fill each group — lighting, power outlets, HVAC and any dedicated equipment — with its connected kW.
4. Set each group demand factor and operating hours to reflect its schedule.
5. Set the building diversity factor (0.8-0.95 is typical).
6. Read the results. Connected, diversified demand, kVA and service class.
7. Export the demand report for the application.

Example 1 — Office. 200 m² office, lighting 500 lux class (12 W/m²), outlets 20 kW, HVAC 25 kW, demand per group 0.9/0.6/0.9, building diversity 0.85: diversified demand lands near 30 kW → ~35 kVA → a 40 kVA supply.

Example 2 — Restaurant. 150 m² kitchen-heavy: lighting 15 W/m², kitchen equipment 40 kW at high demand (0.9), HVAC 15 kW: the kitchen dominates the service decision.

Example 3 — Warehouse. 1,000 m², lighting 8 W/m², little HVAC, low outlet demand: connected looks small but schedule-night charging lifts the diversified total.

Example 4 — Showroom. High lighting density and display power push the lighting group above the outlets.

Example 5 — Shop. 100 m² shopfront: lights all day, small HVAC, modest outlets — a compact 3P supply with headroom.

• Group honesty: Schedules and factors differ per group, exactly as demand really behaves.
• Less oversizing: Diversity stops the panel being sized for everyone switching on at once.
• Lighting without bulb-counting: Density presets size by room purpose and area.
• Schedule-aware: Short-shift equipment stops inflating the service.
• Export-ready: Text, CSV and JSON demand reports for consultants and utilities.
• Free and private: No uploads, no accounts, no logging.