Created By : Naaz Fatima

Reviewed By : Rajashekhar Valipishetty

Last Updated : Apr 10, 2023

dB Calculator over here saves you from hectic calculations and provides the sound pressure level and sound intensity level in decibels. You just need to enter the inputs in the allotted input fields and click on the calculate button to avail the outputs. Utilize it for dB Conversion and finding the distance from source of a sound.

Choose a Calculation
Reference pressure(Pref):

Sound Pressure Level(SPL)

If we hear a loud noise we experience unpleasant feelings that is due to sound waves pressure. This pressure can be measured in pascals and it would be more practical to measure in decibels. Sound Pressure Level is the measure of sound pressure with reference to human hearing threshold.

Formula to determine SPL is given by SPL = 20log(P/Pref)

Where SPL stands for the sound pressure level measured in decibels

P is sound wave pressure in Pascals

Pref is the reference value of sound pressure and is assumed to be 0.00002 Pa

Sound Intensity Level

Sound Intensity Level is the sound wave power per unit area. It is a quantity that allows us to measure the energy per second per one squared meter.

SIL = 10log(I/Iref)

Where SIL is the sound intensity level in decibels

I is the Sound Intensity in Watts Per Squared Meter

Iref is the reference value and is typically 1×10⁻¹² W/m².

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Sound Intensity at a Distance

In general, sound intensity alters with the distance from the sound source. This is just common sense and the phenomenon is known as distance attenuation.

Considering in physical point of view it is just because the ebergy of sound is distributed over a larger area. Consider a sphere is surrounded by a sound source and the sound source is constant. Though the energy emitted by the source is constant sphere gets larger and its surface increases. Energy is distributed over area of sphere. We can write the equation as I = P/(4πR²)

In which R is the radius of sphere and distance from sound source.

Pascals to dB Conversion

We can change between Pascals to Decibels quite easily by using the above formulas listed. You can find the Pascal Values too if you are having the SPL Value.

Frequently Asked Questions on Decibels Calculator

1. How to Calculate Sound Pressure Level?

Sound Pressure Level can be calculated using the formula SPL = 20log(P/Pref)

2. What are the units of Sound Intensity Level?

Units of Sound Intensity Level are Watts Per Meter Squared(W/m┬▓).

3. Is dB a Unit?

Yes, dB is a unit of measuring sound.

4. Define Sound Intensity Level?

Sound Intensity Level is defined as the sound wave power per unit area.