Reverberation Time Calculator
Calculate RT60 using Sabine's formula
Sum of (surface area × absorption coefficient) for all surfaces
How to Use This Calculator
Enter Room Volume
Input the total volume of the room (V) in cubic meters. Calculate this as length × width × height.
Enter Total Absorption
Input the total absorption (A) in m² Sabins. Calculate this by summing (surface area × absorption coefficient) for all room surfaces.
Calculate
Click calculate to get RT60, the time for sound to decay by 60 dB after the source stops.
Formula
RT60 = 0.161 × V / A
where RT60 = reverberation time (seconds), V = room volume (m³), A = total absorption (m² Sabins)
Example:
For a room with volume 500 m³ and total absorption 50 m² Sabins:
RT60 = 0.161 × 500 / 50 = 0.161 × 10 = 1.61 seconds
This means sound will decay by 60 dB in 1.61 seconds after the source stops.
Note: This is Sabine's formula, which assumes diffuse sound field and uniform absorption. For more accurate results, use Eyring's formula or other methods for highly absorptive rooms.
About Reverberation Time Calculator
The Reverberation Time Calculator determines RT60, the time it takes for sound to decay by 60 decibels after the sound source stops. RT60 is a fundamental parameter in architectural acoustics, used to characterize the acoustic properties of rooms and spaces.
When to Use This Calculator
- Architectural Acoustics: Design concert halls, theaters, and auditoriums
- Recording Studios: Optimize room acoustics for recording
- Home Theaters: Design acoustic treatment for home entertainment
- Classroom Design: Ensure proper acoustics for speech intelligibility
- Office Spaces: Control reverberation for comfortable work environments
- Acoustic Engineering: Predict and optimize room acoustic performance
Why Use Our Calculator?
- ✅ Quick Calculations: Get RT60 instantly using Sabine's formula
- ✅ Accurate Results: Uses standard acoustic engineering formulas
- ✅ Easy to Use: Simple interface for volume and absorption input
- ✅ Educational: Learn about reverberation and room acoustics
- ✅ Free Tool: No registration required
Understanding Reverberation Time
Reverberation time (RT60) measures how long sound persists in a room after the source stops. It's a critical parameter that affects speech intelligibility, music quality, and overall acoustic comfort.
- Short RT60 (under 1 second) = "dead" room, good for speech
- Medium RT60 (1-2 seconds) = balanced, good for general use
- Long RT60 (over 2 seconds) = "live" room, good for music
- RT60 depends on room volume and total absorption
- Optimal RT60 varies by application (speech vs. music)
Ideal RT60 Values
- Speech (Classrooms): 0.4-0.6 seconds
- Music (Concert Halls): 1.5-2.5 seconds
- Home Theaters: 0.3-0.5 seconds
- Recording Studios: 0.2-0.4 seconds (control rooms)
- Churches: 1.5-3.0 seconds
Frequently Asked Questions
What is RT60?
RT60 is the reverberation time, defined as the time it takes for sound to decay by 60 decibels after the sound source stops. It's measured in seconds and characterizes how "live" or "dead" a room sounds.
What is Sabine's formula?
Sabine's formula is RT60 = 0.161 × V / A, where V is room volume and A is total absorption. It assumes a diffuse sound field and is most accurate for rooms with moderate absorption (A/V < 0.2).
How do I calculate total absorption (A)?
Total absorption is the sum of (surface area × absorption coefficient) for all room surfaces. For example, if a wall has 20 m² area and 0.3 absorption coefficient, it contributes 6 m² Sabins to the total.
What is a Sabin?
A Sabin is a unit of acoustic absorption, equal to 1 square meter of perfectly absorbing surface. It's named after Wallace Sabine, the founder of architectural acoustics.
When should I use Eyring's formula instead?
Use Eyring's formula (RT60 = 0.161 × V / (-S × ln(1 - ᾱ))) for rooms with high absorption (A/V > 0.2), where S is total surface area and ᾱ is average absorption coefficient. Sabine's formula becomes inaccurate for highly absorptive rooms.