MBE / HUB-Certified Texas MEP
Electrical Service Demand Calculator
Quick estimator for commercial service entrance amps per NEC Article 220 simplified method (general lighting + receptacle + HVAC + cooking + other connected load × demand factor). Use for early-phase service-size budgeting before final panel-by-panel calc.
Sets per-sf load assumption for general lighting/receptacle.
Conditioned floor area.
Most TX commercial: 208 for under-50kVA loads; 480 above.
Sum of cooking equipment, HVAC compressors, motors not included in base /sf rate.
Estimated service amps
200A
Basis: 3,000 sf retail × 3 VA/sf + 20 kW equipment = 9 + 20 = 29 kVA at 208V three-phase = 80 A × 1.25 (continuous) ≈ 100 A. Recommended service: 200 A (next standard, with 100% future headroom).
100% headroom
We recommend rounding service entrance up to next standard size with at least 100% future headroom. Tenant-improvement projects routinely add load over the building life; oversized service is cheap insurance.
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Important. This is a simplified early-phase estimator. NEC Article 220 has detailed calculation methods (Standard, Optional, Farm) with demand factors per Article 220 Parts II-V. Final service entrance for permit requires full NEC 220 calc by a licensed engineer.