CFM Calculator
Calculate airflow requirements for HVAC systems
Why this tool matters
Solve the calculation or lookup now, then keep the answer attached to the installed base so it can support maintenance follow-up, warranty timing, equipment history, and replacement conversations later.
Next best step
Use the result in the field, then start a free AssureStep account when you want the context to stay visible after this visit.
Quick Reference
Standard Airflow
400 CFM per ton of cooling
Example: 3-ton = 1,200 CFM
Formula
CFM = BTU ÷ (1.08 × ΔT)
ΔT = Temperature difference
Low Airflow Issues
< 350 CFM/ton: Poor efficiency, frozen coils
High Airflow Issues
> 450 CFM/ton: Poor dehumidification
Understanding CFM
CFM (Cubic Feet per Minute) measures how much air your HVAC system moves.
Industry Standard: 400 CFM per ton of cooling capacity
Range: 350-450 CFM per ton is acceptable for most systems
Why it matters: Proper airflow ensures efficiency, comfort, and prevents equipment damage
Track System Performance Over Time
AssureStep AssureStep gives you unlimited equipment tracking, CSV import, and alerts you to airflow issues before they cause callbacks.