Free Tool
Enter your room dimensions and materials. Get an estimated acoustic score, reverberation time, room modes, and personalized fix recommendations — instantly.
This calculator estimates reverberation time (RT60) from your room's dimensions and surface materials. RT60 is the time it takes for sound to decay by 60 decibels — the standard measure of how “echoey” a room sounds.
It uses the Eyring-Norris equation rather than the more common Sabine equation. Sabine assumes absorption is low and evenly spread, which holds in a large reflective hall but breaks down in a small, well-furnished or treated room — exactly the rooms people ask about. In that regime Sabine overstates reverberation time, so we use the formula that doesn't.
Absorption figures come from our database of 90 measured materials, quoted per octave band from 125 Hz to 4 kHz — because almost no material absorbs evenly across frequency, and treating absorption as a single number is how people end up buying the wrong thing.
Room modes are calculated using the Rayleigh equation, which predicts the frequencies where standing waves form based on room dimensions. These are the bass frequencies that build up and make a room sound “boomy.”
If the calculator says your room is too live, the acoustic panel calculator works out how many panels it would take to reach your target — and what a smaller number would get you instead.
It depends on the room. A home office or recording studio should be around 0.3–0.4 seconds. A living room is comfortable at 0.4–0.6 seconds. A kitchen or dining room can tolerate 0.5–0.7 seconds. Too high means echoes and poor speech clarity. Too low means the room feels dead and uncomfortable.
This calculator provides an estimate based on idealized conditions — it assumes uniform materials, no furniture, and simple rectangular geometry. Real rooms have furniture, doors, irregular shapes, and variable materials that affect acoustics. For an accurate measurement of your actual room, use the RoomTone app — it listens to how sound actually behaves in your space.