Living Room CFM Calculator
Supply airflow for a living or family room.
Enter your values
Enter the room area in sq ft.
Choose one of: Little glass, Average, Large windows.
Enter the typical occupants you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Supply airflow
- 384 CFM
- Fresh air component
- 30 CFM
- Registers at 120 CFM each
- 4
- Trunk duct at 800 FPM
- 9.4 in dia
Quick answer
Living rooms usually need 1-1.5 CFM per square foot, with more airflow for large glazed areas.
CFM = area x rate x glazing factor
At a glance
| What it does | Supply airflow for a living or family room. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Room area, Glazing, Typical occupants |
| Main output | Supply airflow |
| Formula | CFM = area x rate x glazing factor |
| Cost | Free — no sign-up, no download |
How to use the Living Room CFM Calculator
- 1Measure the room and judge how much glass it has.
- 2Split the total across two or more registers for even mixing.
- 3Place supplies near the glazing to wash the cold surfaces.
Inputs explained
- Room area(sq ft)
- Enter the room area in sq ft.
- Glazing
- Choose one of: Little glass, Average, Large windows.
- Typical occupants
- Enter the typical occupants you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- Room area320 sq ft
- GlazingAverage
- Typical occupants4
Results
- Supply airflow384 CFM
- Fresh air component30 CFM
- Registers at 120 CFM each4
- Trunk duct at 800 FPM9.4 in dia
Frequently asked questions
Why more air near windows?
Glass is the biggest load; blowing air across it stops cold downdrafts in winter.
Open plan?
Treat the whole open area as one zone and total the areas.
What do I need to enter into the Living Room CFM Calculator?
Just 3 values: room area, glazing, typical occupants. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Living Room CFM Calculator work out the answer?
Living rooms usually need 1-1.5 CFM per square foot, with more airflow for large glazed areas. It applies the formula CFM = area x rate x glazing factor and shows the working so you can check each step by hand.
Is the Living Room CFM Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.