Diffuser Count Calculator
Number of ceiling diffusers for a space.
Enter your values
ⓘ Live results
Results
- Diffusers needed
- 4
- Actual coverage each
- 150 sq ft
- Suggested layout
- 4 in a row or grid
Quick answer
Diffuser count is the room's floor area divided by each diffuser's effective coverage area, rounded up to a practical layout.
Count = room area / coverage area per diffuser
How to use the Diffuser Count Calculator
- 1Enter the total floor area to be served by ceiling diffusers.
- 2Enter each diffuser's rated coverage area (based on throw and ceiling height).
- 3Round up and lay out diffusers evenly across the space.
Worked example
Using the values the calculator loads with:
Inputs
- Room area600 sq ft
- Coverage per diffuser150 sq ft
Results
- Diffusers needed4
- Actual coverage each150 sq ft
- Suggested layout4 in a row or grid
Frequently asked questions
What affects coverage per diffuser?
Ceiling height, diffuser throw pattern and airflow per unit all change effective coverage.
Can I use fewer, larger diffusers?
Yes, but very high CFM diffusers can create drafts; a moderate number of medium diffusers usually gives more even comfort.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.