For anyone wishing to acoustically treat a room, the RT60 Calculator v2 is a must for calculating how much absorption is required to achieve a desired level of natural reverberation in a room. RT60 Calculator v2 can be used to calculate the amount of time sound will be present in a room as reverberation after the sound has stopped. It then displays this information in both numerical form (seconds) and in a visual form (bar graph). Just put in the room dimensions and you’re away! It supports the modelling of a room with a door, a window and an optional amount of porous absorption too. You can enter absorption coefficients manually or copy / paste them from the web.