Free · Physics models
Rectangular Room Reverberation Estimate
Estimate Sabine decay time from room dimensions and separate surface absorption coefficients.
- Formula & worked example
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Calculator inputs
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How to use this calculator
- Enter the known values in the units shown. Results update as you type.
- Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
- Use the worked example to check the method. Reset restores the starting fields.
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Formula and method
Effective absorbing area = 17.300000; Reverberation time = 0.18843931. The worked example lists its inputs and unit conventions.
T60 = 0.163 V/Aabs, where Aabs = Σ surface area × absorption coefficient.
Worked example
Enter these known values and leave the other values blank.
- Room length
- 5 m
- Room width
- 4 m
- Room height
- 1 m
- Door height
- 200 cm
- Door width
- 100 cm
- Number of doors
- 1
- Windows height
- 100 cm
- Windows width
- 100 cm
- Number of windows
- 1
- Walls
- 0.2
- Ceiling
- 0.3
- Floor
- 0.4
- Doors
- 0.1
- Windows
- 0.1
- Effective absorbing area
- 17.3 m²
- Reverberation time
- 0.19 sec
Assumptions and limitations
- The fixed 0.163 s/m coefficient is a rounded room-acoustics approximation for a diffuse sound field. Coefficients depend on frequency and mounting. Doors and windows replace wall area and must fit within the total wall area.
- Clear the quantity to solve an inverse; keep known quantities fixed with locks. Some inverses are singular or ambiguous and require further known values.
- Unit selectors convert the same physical quantity. Rounded reference constants and presets limit physical accuracy even when arithmetic displays more digits.
Common questions
What does this model assume?
The fixed 0.163 s/m coefficient is a rounded room-acoustics approximation for a diffuse sound field. Coefficients depend on frequency and mounting. Doors and windows replace wall area and must fit within the total wall area.
Can I solve for an input?
Editable calculated fields support the captured inverse relationships. Clear the unknown and supply enough independent known values; an inverse must remain within the declared physical domain.
References
Enforce the reviewed model domain: Door count must be a whole number. Window count must be a whole number. Total openings cannot exceed the total wall area.