Generator Size Calculator

Find the right generator size for residential or commercial loads.

Add each load below. Motors require 3–6× rated current at start-up.

W
W
W
W
PF
%
Generator Recommendation

Formulas

  • kVA running = Total watts × surge factor / (PF × 1000)
  • kVA sized = kVA running × (1 + margin%/100)
  • Standard generator sizes: 3.5, 5, 7.5, 10, 14, 20, 25, 30, 40, 60, 80, 100 kVA