Reverb-Calculator.com is a free educational website providing browser-based room acoustics calculation tools and educational content about RT60 reverberation time, acoustic formula methodology, absorption coefficients, and room design targets — built for acoustic engineers, architects, studio designers, educators, and anyone making decisions about how sound behaves in an enclosed space.
The site was created and is maintained by Noah Bennett, an acoustic engineer and room acoustics educator with expertise in RT60 calculation, Sabine and Eyring formula methodology, absorption coefficient science, and room acoustic design for recording studios, classrooms, concert halls, and home theatres.
Why This Site Exists
RT60 — the time it takes for sound to decay by 60 decibels in an enclosed space — is the most important single measurement in architectural acoustics. It determines whether a concert hall sounds rich or muddy, whether a recording studio produces clean takes or coloured recordings, whether a classroom supports speech intelligibility or undermines it, whether a home theatre delivers cinematic immersion or unwanted echo.
The Sabine equation, derived by Wallace Clement Sabine at Harvard University in 1898, makes RT60 calculable from three inputs: room volume, total surface area, and the absorption coefficients of the surfaces. That is all the information you need. Yet most RT60 calculators online show a result without explaining the formula, without documenting which version of the constant they use (0.161 for metric, 0.049 for imperial), without noting when the Eyring equation would give more accurate results, and without connecting the result to the target range appropriate for the room’s intended use.
Reverb-Calculator.com was built to close that gap — to give anyone making acoustic decisions a calculation tool paired with the physical understanding that makes the result actionable.
What the Site Provides
Reverb-Calculator.com has two areas of tools and educational content:
Room acoustics calculation tools — browser-based tools that calculate RT60 from room dimensions and material properties. No microphone, no audio capture, no downloads required:
- Reverb Calculator — the flagship tool: enter room volume, total surface area, and average absorption coefficient to calculate RT60 using the Sabine equation
- Additional tools calculating RT60 using the Eyring equation for highly absorptive rooms, absorption in Sabins from individual surface contributions, and room type target comparisons
Educational content covering four areas:
- Acoustic formulas and RT60 science — the Sabine and Eyring equations, their derivations, the physical meaning of absorption coefficients, how frequency affects reverberation time, and how early reflections and late reverberation differ
- Room design targets — established RT60 target ranges for recording studios (0.2–0.6s), vocal booths (0.2–0.4s), home theatres (0.3–0.5s), classrooms (0.6–0.9s), conference rooms (0.4–0.6s), concert halls (1.5–2.5s), and other space types, with the acoustic reasoning behind each range
- Absorption coefficients and material selection — how absorption coefficients are measured and expressed, how common building and finishing materials perform acoustically, and how to apply published coefficient data in RT60 calculations
- Room acoustics fundamentals — how sound propagates in enclosed spaces, what causes flutter echo and standing waves, why room geometry matters for acoustic quality, and how to approach acoustic treatment decisions
Who This Site Is For
Reverb-Calculator.com is built for:
- Acoustic engineers and consultants needing a fast, accurate online RT60 reference and calculation tool
- Architects and interior designers making material selections with acoustic performance in mind
- Recording studio designers and builders calculating RT60 targets and treatment requirements for studios, control rooms, and vocal booths
- Home studio musicians wanting to understand their room’s acoustic behaviour and how to improve it
- Home theatre designers optimising a room for cinematic audio performance
- Educators and students in architectural acoustics, audio engineering, and building physics programmes
- Facility managers and building professionals assessing classroom, office, or workspace acoustic performance
Calculation Accuracy
The calculation tools on this site produce mathematically exact results based on the Sabine and Eyring formulas as published in the acoustic science literature. The Sabine constant of 0.161 (metric) and 0.049 (imperial) are correctly applied. Input units are clearly specified to prevent calculation errors from mixing unit systems.
The tools document their assumptions — the Sabine formula assumes a diffuse sound field and uniformly distributed absorption, and these assumptions have consequences for accuracy in rooms with irregular geometry or highly non-uniform treatment. Where the Eyring formula provides more accurate results (rooms with average absorption coefficient above approximately 0.3), this is noted and the Eyring calculation is available alongside the Sabine result.
The full technical explanation of the formulas and their application is in the How It Works page. Research and editorial standards are in the Editorial Guidelines page.
Get in Touch
Questions, corrections, and feedback are welcome. Contact us via the Contact page. All messages are reviewed personally by Noah Bennett.
Reverb-Calculator.com is an independent educational website. It is not affiliated with any acoustic standards body, architecture firm, or audio equipment manufacturer.
Founded and maintained by Noah Bennett — acoustic engineer and room acoustics educator. Last updated: June 2026.