Kitchen Range Hood CFM & Makeup Air Damper Calculator
Calculate required kitchen range hood exhaust airflow (CFM) across cooktop burner BTU, mounting style (wall vs island), and room air changes, and determine code-mandated Makeup Air (MUA) damper duct sizing per IRC Section M1503.6.
Cooktop & Kitchen Specifications
BTU/hr
Sum of all gas burner maximum ratings.
Inches
Recommended Range Hood CFM
MAKEUP AIR REQUIRED (>400 CFM)
600 CFM
Governed by gas burner heat output (100 CFM per 10,000 BTU)
IRC M1503.6 Code Status
MANDATORY MUA
Exhaust exceeds 400 CFM limit
Makeup Air Duct Size
8" Round Duct
Interlocked motorized damper per IRC M1503
Sizing Breakdown by Methodology
Gas Burner Heat Rule (100 CFM / 10k BTU):
600 CFM
Perimeter Width Rule:
300 CFM
Kitchen Air Exchange (15 ACH):
504 CFM