While professionals use tools like anemometers to measure cubic feet per minute airflow accurately, homeowners can estimate CFM on their own with simple calculations. By measuring the room’s dimensions and using the ACH (air changes per hour) method, you can determine a general estimate of the CFM needed for each room. However, it’s important to note that DIY methods may not be as precise as professional assessments, especially if there are other factors like duct leaks or poor system design affecting airflow. For a precise evaluation, consider contacting an HVAC professional.