# DECIBEL (dB) CONVERTER

Decibel (dB) converter is a online tool for decibel - ratio conversion, multiplication of dB value by a number and addition and subtraction operations of values in dB. Formulas for dB calculations such as decibel field ratio calculation, decibel power ratio calculation, adding decibels, subtracting decibels and multiplication of decibel by a number are given in the "List of Equations" section of this page.

##### Calculator:

 dB - Ratio conversion Magnitude type Power Field Conversion type dB to ratio ratio to dB
 Ratio (factor) Decibel
 Multiplication by a number (n * B(dB) = A(dB)) Relationship n B  (dB) A (dB) Power Field
 Addition / Subtraction (LA(dB) ± LB(dB) = Result) Relationship LA (dB) LB  (dB) Result Addition Subtraction

##### Definitions:

Decibel (dB): Decibel is a unit used to express relative difference in power or intensity, usually between two acoustic or electric signals, equal to ten times the common logarithm of the ratio of the two levels.

Examples to power quantities: Sound power measurements, power spectral density random vibration.

Examples to field quantities:  Voltage, displacement, velocity, acceleration, force, sound pressure, strain.

Reference  acoustic sound pressure level dB(SPL) : The lowest sound pressure which is usually considered the threshold of human hearing (at 1 kHz) is approximately 2*10-5Pa .

##### List of Equations:

 The power relationship in dB The field relationship in dB Multiplication by a number n for power relationship Multiplication by a number n for field relationship Addition of dB Subtraction of dB