RT60 Reverb Time Estimator
Estimate a room's reverb time from its dimensions and surface absorption with the Sabine formula, and see whether the space needs acoustic treatment for clean voice.
Fix the room, not just the mic
A great microphone in a reflective room still sounds boxy, because it captures the room's reverb along with your voice. Estimating RT60 from your space's size and surfaces tells you whether that reverb is short enough for clean speech or long enough to need treatment — and how much soft, absorbent material would bring it under control. It is often the highest-impact, lowest-cost upgrade a home recordist can make.
Pair a treated room with consistent mic distance for the cleanest possible source recording.
Frequently Asked Questions
What is RT60?
RT60 is the time it takes for a sound to fade by 60 decibels — effectively how long the room 'rings' after the source stops. A short RT60 sounds dry and controlled; a long one sounds echoey and boxy. It is the single most useful number for describing how a room will treat a recorded voice.
How does the Sabine formula work?
The Sabine equation estimates RT60 = 0.161 × room volume ÷ total absorption, where total absorption is the room's surface area multiplied by its average absorption coefficient (in metric units). This tool computes the volume and surface area from the length, width, and height you enter, applies your chosen average absorption, and returns the reverb time.
What RT60 is good for a podcast or voice recording?
For spoken word, aim for a short reverb time of roughly 0.3 to 0.5 seconds. That keeps speech clear and intimate without sounding unnaturally dead. Much above that and the room adds a hollow, distant quality; a heavily treated vocal booth may sit below it, which is fine for voice though it can feel flat for music.
What absorption coefficient should I choose?
A bare room with tile, glass, or drywall absorbs very little — around 0.05. Carpet, curtains, and a sofa push the average toward 0.2, a room with dedicated acoustic panels toward 0.35, and a heavily treated space or booth toward 0.5. Pick the option that best matches your room's soft, absorbent surfaces; adding more of them is what lowers the reverb time.
A Sabine estimate assumes reasonably even absorption and no strong flutter echoes; real rooms vary. Confirm by ear or with a measurement. Not professional acoustic-engineering advice.