Skip to main content

learn.howToCalculate

learn.whatIsHeading

HVAC Duct Sizing Calculator helps contractors and tradespeople accurately size, spec, and estimate materials and systems.

Formule

Duct Area = CFM / (FPM velocity) where FPM = 700-900 for mains

Guide étape par étape

  1. 1Calculate required CFM per room, size duct for target velocity
  2. 2Apply the formula using your project measurements
  3. 3Add required safety factors or waste allowances per code

Exemples résolus

Entrée
400 CFM, 800 FPM target
Résultat
Area = 400/800 = 0.5 sf → 8×9 inch duct

Erreurs courantes à éviter

  • Not applying code-required safety factors or derating
  • Forgetting to account for waste and cut losses in material estimates

Prêt à calculer ? Essayez la calculatrice gratuite Duct Sizing

Essayez-le vous-même →

Paramètres