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Sound Level Converter

Convert sound pressure in pascals and dB SPL, or acoustic intensity in W/m² and dB, with explicit references and correct logarithmic formulas.

Convert instantly
Enter a value and choose the units. Your answer updates as you type.

Sound pressure (Pa and dB SPL) and sound intensity (W/m² and dB) use different references. Selecting one family automatically pairs the other unit within that family.

Result

93.9794000867 Sound pressure level (dB SPL re 20 µPa)

Quick reference
  • Sound pressure (Pa)1 base units
  • Sound pressure level (dB SPL re 20 µPa)1 base units
  • Sound intensity (W/m²)1 base units
  • Intensity level (dB re 1 pW/m²)1 base units

About the Sound Level Converter

Sound levels cannot be converted safely without naming the physical quantity and its reference. This page keeps sound pressure (20 log₁₀(p/20 µPa)) separate from intensity (10 log₁₀(I/1 pW/m²)); a pressure decibel and an intensity decibel are not interchangeable.

For example, 20 µPa is 0 dB SPL and 200 µPa is 20 dB SPL. An intensity ten times the 1 pW/m² reference is 10 dB. Use the Power Converter for ordinary electrical power, and the Frequency Wavelength Converter when frequency—not level—is the quantity being studied.

Frequently asked questions

What does the sound level measure?

Decibels are logarithmic: pressure or amplitude ratios use 20 log₁₀, while power and intensity ratios use 10 log₁₀. Sound pressure level uses the explicit 20 µPa reference, and intensity level here uses 1 pW/m².

What is a useful reference conversion for sound level?

20 µPa is 0 dB SPL; 10× the pressure is 20 dB SPL, while 10× the intensity is 10 dB.

Are the factors on this page exact?

SI prefixes and internationally defined units use their standard factors. Legacy and customary factors are retained at their published scientific definitions and may be rounded only for display.

Take this calculation further

Browse the converters calculators collection for more tools in this subject.

For a related calculation, use Luminance Converter to convert luminance between candela per square metre, foot-lambert, stilb, and related photometric units. Alternatively, use Frequency Wavelength Converter to convert electromagnetic frequency and vacuum wavelength using the exact speed of light, from hertz and gigahertz to metres and nanometres.

For the underlying method, read Understanding Sound Decibels: Why the Scale Isn't Linear.