RT60 Calculator

Estimate RT60, the time it takes sound to decay by 60 dB in a room. Enter room dimensions and average absorption to calculate room volume, surface area, equivalent absorption area, and estimated reverberation time.

Calculate RT60

RT60 = 0.049 × V ÷ A
Your result will appear here.

How the RT60 calculator works

Room volume:
The calculator multiplies room length, width, and height to estimate room volume.

Total surface area:
The floor, ceiling, and wall areas are added together to estimate the total room surface area.

Absorption area:
The surface area is multiplied by the average absorption coefficient to estimate equivalent absorption area.

Why use an RT60 calculator?

An RT60 calculator helps estimate whether a room may sound dry, balanced, live, or overly reverberant. It can be useful for studios, classrooms, offices, home theaters, churches, rehearsal rooms, restaurants, and meeting spaces.

This is a simplified estimate. Real acoustic design may require frequency-band calculations, actual material absorption data, seating details, furniture, doors, windows, and on-site measurements.

RT60 formula

This calculator uses a simplified Sabine-style RT60 formula:

RT60 = 0.049 × V ÷ A when using feet

RT60 = 0.161 × V ÷ A when using meters

RT60 calculator tips

Frequently asked questions

What does RT60 mean?

RT60 means the time it takes sound in a room to decay by 60 decibels after the sound source stops.

What is a good RT60?

For speech rooms, a lower RT60 is usually better. Many offices, classrooms, and meeting rooms are often more comfortable around roughly 0.4 to 0.8 seconds.

How do I lower RT60?

You can lower RT60 by adding absorption such as acoustic panels, carpet, curtains, upholstered furniture, ceiling clouds, or other sound-absorbing materials.

Is RT60 the same at every frequency?

No. RT60 can be different at low, mid, and high frequencies because materials absorb different frequencies by different amounts.