Explains the distinction between apparent power (kVA) and real power (kW) on a transformer nameplate, and why sizing a transformer purely against a building's sanctioned kW load — without accounting for power factor — is a common and consequential mistake. Covers connected load vs. actual demand with diversity factors, ambient temperature and cooling-class derating specific to Indian conditions, a worked sizing example across motor, lighting, and HVAC load categories, and parallel transformer operation requirements (matching vector groups and impedance). References IEC 60076 and IS 2026. General technical education on electrical distribution design — actual transformer selection should be verified by a qualified electrical engineer. See our https://6a7d436a1f961.site123.me/blog/what-a-transformer-s-kva-rating-actually-tells-you-about-load-capacity for our power factor correction guide and https://enarayan.com/products/switchgear/ for our transformer and switchgear range. eNarayan Elex, Rasoolpura, Hyderabad.