🏛️ Reverb Time (RT60) Calculator
Enter your room's dimensions and how absorptive it is to estimate the reverberation time.
Reverb time (RT60)
0.54 s
Room volume
72 m³
Total absorption
21.6 sabins
Fairly controlled — suits studios, home theatres and critical listening.
RT60 is the time for sound to fade by 60 dB (to near silence). The Sabine equation estimates it as RT60 = 0.161 × room volume ÷ total absorption, where absorption = surface area × the average absorption coefficient. Soft, porous materials absorb more (higher coefficient) and shorten the reverb; hard surfaces reflect and lengthen it. This uses one average coefficient — real rooms vary by frequency and material. 🔒 In your browser.
How the reverb time (rt60) calculator works
Reverberation time (RT60) is how long a sound takes to fade by 60 decibels — effectively to silence — after it stops. The Sabine equation estimates it from the room's volume and how much sound its surfaces soak up: RT60 = 0.161 × volume ÷ total absorption, where total absorption (in "sabins") is the surface area times an average absorption coefficient. The tool works out the volume and surface area from your length, width and height, applies the coefficient for your room type, and reports RT60 with a plain-language verdict.
This uses a single average absorption coefficient, so it's a ballpark — real rooms absorb differently at each frequency and with each material, and furnishings matter a lot. Typical targets: about 0.3–0.5 s for a control room or home studio, 0.4–0.6 s for a listening room or home cinema, up to 1.5–2.5 s for a concert hall. Adding soft, porous material (curtains, carpet, acoustic panels) raises absorption and shortens the reverb.
Frequently asked questions
What is RT60?
The reverberation time — how long it takes a sound to decay by 60 dB after the source stops. A short RT60 (a "dead" room) suits recording and speech clarity; a long one (a "live" room) adds a sense of space to music.
What is the Sabine equation?
RT60 = 0.161 × V ÷ A (metric), where V is the room volume in cubic metres and A is the total absorption in sabins (surface area × average absorption coefficient). It's the classic formula for estimating reverberation time.
What is a good reverb time for a room?
It depends on use: about 0.3–0.5 s for a studio control room, 0.4–0.6 s for a home theatre or listening room, 0.6–1.0 s for a living room, and 1.5–2.5 s for a concert hall. Speech needs shorter times than orchestral music.
How do I reduce reverb in a room?
Add absorption: soft furnishings, thick curtains, carpet or rugs, upholstered furniture, bookshelves and acoustic panels all raise the absorption coefficient and shorten RT60. Hard, bare surfaces (glass, tile, plaster) do the opposite.
How accurate is this estimate?
It's a first approximation. Sabine's formula assumes a fairly reverberant room with evenly spread absorption and uses one average coefficient, whereas real absorption varies by frequency and material. Use it to plan treatment, then measure to confirm.