RT60 Acoustic Calculator.
Room dimensions and finish materials in, indicative RT60 reverberation time and recommended absorber area out. Sabine equation; defensible for early-stage acoustic planning.
- Boardroom target
- 0.4–0.6 s
- Cinema target
- 0.3–0.4 s
- Mastering
- 0.2–0.3 s
- Standard
- ISO 3382
— Acoustic · RT60 · Sabine model
The room's reverberation time.
Room volume + finish materials in, indicative RT60 + recommended absorber area out. Sabine's equation; real-world results validated with on-site measurement.
Room volume
144 m³
Office / classroom
Calculated RT60
0.67 s
Within target
Total absorption (A)
34.6 Sabins
Sum of surface × coef
Target RT60
0.5 — 0.7 s
for this room volume
Recommended treatment
4.8 m²
Add this much premium 50mm fabric-wrapped absorber area to hit the room's RT60 target. Distribute across walls and ceiling — never just one surface.
Sabine model is a first-order estimator — actual room behaviour validated on-site with a calibration microphone and impulse measurement. For cinemas and recording studios we model in EASE before committing to specification.
· Why it matters
A boardroom with a 0.45 RT60 sounds clear in person and on the conference call. The same room at 0.9 — bare drywall, glass tables, hard ceiling — turns every voice into a smear and every video meeting into a request to repeat. RT60 is the single number that separates one from the other, and it is decided by absorber area before drywall ever goes up.
· Frequently asked
RT60 —
what people ask first.
What is RT60 and why 60 decibels?
RT60 is the time, in seconds, for a sound to decay by sixty decibels — roughly the drop from a normal voice to inaudible. It is the standard measure of reverberation across acoustic engineering, ISO 3382 and most cinema and broadcast specifications.
What inputs do I need?
Room length, width and height, plus the dominant finish materials on floor, walls and ceiling. The calculator uses Sabine absorption coefficients and gives a single mid-band RT60 — accurate enough for the first design conversation.
Is the Sabine equation accurate enough for cinemas?
For early-stage planning, yes. Sabine assumes a diffuse field, which holds well for rectangular rooms with mixed finishes. Reference cinemas, mastering rooms and recording spaces still need a measured RT60 with calibrated equipment, plus modal analysis below 200 Hz.
What RT60 should I target?
Boardrooms and conference rooms: 0.4 to 0.6 seconds. Home cinema: 0.3 to 0.4. Recording or mastering: 0.2 to 0.3. Lecture halls and worship halls: 0.8 to 1.2 depending on volume. The tool flags the band for your selected room type.
Will you size and supply the absorbers?
Yes. We design and install acoustic treatment as part of cinema, boardroom and listening-room projects — fabric-wrapped panels, diffusers and bass traps, sourced from European manufacturers and tuned on site after install.
· Begin
Treating a room
that has to sound right?
Send the room dimensions, intended use and any acoustic measurements you already have. We will write back with a treatment plan within two working days.