Sabine surface absorption worksheet
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Fix: Subtract the covered area from the original finish and enter the replacement area once.
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Sabine surface absorption worksheet
Estimate frequency-specific room reverberation from volume and documented surface absorption.
01Enter your values
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02Sabine surface absorption worksheet
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How it works
Estimate frequency-specific room reverberation from volume and documented surface absorption.
RT₆₀ = 0.161 V / Σ(Sᵢαᵢ)
A diffuse sound field and relatively low, distributed absorption are assumed. Concentrated ceiling absorption, room modes, air attenuation and scattering can invalidate this preliminary estimate. Do not add treatment over an unchanged full surface: split replacement areas. Coefficients are supplied by the user; values above 1 are outside this bounded model. No compliance or intelligibility rating. Works offline after loading.
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Inputs are processed on this page and are never sent to a server.
About this tool
Use tool ↑Estimate frequency-specific room reverberation from volume and documented surface absorption.
Sum surface area times absorption coefficient to obtain equivalent absorption area A. Estimate RT60 = 0.161 × volume / A using m³ and m². The area-weighted mean coefficient is A divided by total surface area. Convert geometry to base units first; all coefficients must refer to the same frequency and mounting.
How to use it
- Enter your values
Room volume · Coefficient frequency · Surface areas
- Calculate / generate
Estimate frequency-specific room reverberation from volume and documented surface absorption.
- Result
Estimated RT60: 1.2075 s Equivalent absorption area: 20 m² Area-weighted coefficient: 0.1
Calculation method
- Sum surface area times absorption coefficient to obtain equivalent absorption area A.
- Estimate RT60 = 0.161 × volume / A using m³ and m².
- The area-weighted mean coefficient is A divided by total surface area.
- Convert geometry to base units first; all coefficients must refer to the same frequency and mounting.
RT₆₀ = 0.161 V / Σ(Sᵢαᵢ)
Sabine surface absorption worksheet
- Room volume
- 150 m³
- Coefficient frequency
- 1000 Hz
- Surface areas
- Surface area: 50, Absorption coefficient: 0.1 Surface area: 50, Absorption coefficient: 0.2 Surface area: 100, Absorption coefficient: 0.05
Result
Estimated RT60: 1.2075 s Equivalent absorption area: 20 m² Area-weighted coefficient: 0.1
Frequently asked questions
What does this result assume?
A diffuse sound field and relatively low, distributed absorption are assumed. Concentrated ceiling absorption, room modes, air attenuation and scattering can invalidate this preliminary estimate. Do not add treatment over an unchanged full surface: split replacement areas. Coefficients are supplied by the user; values above 1 are outside this bounded model. No compliance or intelligibility rating. Works offline after loading.
Where does my data go?
Calculations run on your device. Form inputs are not sent to a server.
Terms and definitions
Enter your values
- Measurement system
The initial choice follows your browser region. Your choice is remembered on this device. Gallons are US gallons. Switching units keeps your numbers unchanged and interprets them in the new unit.
Numbers stay unchanged. Check the new unit and enter the intended measurement, or select an example for that system.
- Room volume
Net enclosed air volume in the selected unit.
Enter a numerical value for this quantity. Use the unit shown beside this field. m³ / ft³
Minimum: 1e-12 · Maximum: 1000000000000 m³
- Coefficient frequency
Frequency in Hz shared by all supplied absorption coefficients; a record label, not a frequency conversion.
Enter a numerical value for this quantity. Use the unit shown beside this field. Hz
Minimum: 1e-12 · Maximum: 1000000000 Hz
- Surface areas
Include each physical boundary once; subdivide surfaces with different treatments.
Enter one item per row; each column describes that item.
- Surface area
Area of this surface or subdivision in the displayed unit.
Enter a numerical value for this quantity. Use the unit shown beside this field. m² / ft²
Minimum: 1e-12 · Maximum: 1000000000000 m²
- Absorption coefficient
Documented coefficient from 0 to 1 for this surface, frequency and mounting.
Enter a numerical value for this quantity.
Minimum: 0 · Maximum: 1
Result
- Result
Sum surface area times absorption coefficient to obtain equivalent absorption area A. Estimate RT60 = 0.161 × volume / A using m³ and m². The area-weighted mean coefficient is A divided by total surface area. Convert geometry to base units first; all coefficients must refer to the same frequency and mounting.
Calculated from your entries using the method below.
- Estimated RT60
Predicted time in seconds for a 60 dB decay under Sabine assumptions.
Calculated from your entries using the method below.
- Equivalent absorption area
Sum of surface areas multiplied by their coefficients.
Calculated from your entries using the method below.
- Area-weighted coefficient
Equivalent absorption area divided by the total listed surface area.
Calculated from your entries using the method below.
- Value
Sum surface area times absorption coefficient to obtain equivalent absorption area A. Estimate RT60 = 0.161 × volume / A using m³ and m². The area-weighted mean coefficient is A divided by total surface area. Convert geometry to base units first; all coefficients must refer to the same frequency and mounting.
Calculated from your entries using the method below.
- Unit
Convert geometry to base units first; all coefficients must refer to the same frequency and mounting.
Calculated from your entries using the method below.
Common mistakes and quick fixes
Limits and key assumptions
- A diffuse sound field and relatively low, distributed absorption are assumed. Concentrated ceiling absorption, room modes, air attenuation and scattering can invalidate this preliminary estimate. Do not add treatment over an unchanged full surface: split replacement areas. Coefficients are supplied by the user; values above 1 are outside this bounded model. No compliance or intelligibility rating. Works offline after loading.
- Displayed results may be rounded; rounding does not add measurement precision.