Free Transformer Sizing Calculator

Determine the required transformer kVA rating from the connected three-phase load.

kW
%
%

Required kVA (with growth)

226 kVA

Maximum Demand160.0 kW

Required kVA (with growth) vs Total Connected Load

Transformer Sizing

The transformer must handle the maximum demand load with adequate margin.

Method

Maximum demand = Total connected load x Demand factor

Required kVA = Max demand (kW) / Power factor x (1 + Growth margin)

The demand factor accounts for the fact that not all loads operate simultaneously. The growth margin reserves capacity for future expansion (typically 15-25%).

Example Calculation

200 kW total connected load, 80% demand factor, 0.85 PF, 20% growth.

  1. 01Maximum demand = 200 x 0.80 = 160 kW
  2. 02Required kVA = 160 / 0.85 x 1.20 = 225.9 kVA
  3. 03Select the next standard size: 250 kVA transformer.

Frequently Asked Questions

Learn More

Beam Stress Calculation Guide: From Theory to Practice

Learn how to calculate beam stress step by step. Covers bending stress, shear stress, the flexure formula, stress distributions, and practical design checks for structural beams.

Related Calculators