Decibel Addition Subtraction Calculator for addition and subtraction operations of values in dB. Formulas for adding and subtracting decibels are given below the calculator.

 Addition / Subtraction (LA(dB) ± LB(dB) = Result) Relationship LA (dB) LB  (dB) Result Addition Subtraction

Note: Use dot "." as decimal separator.

Note: For addition and subtraction operation, LA ≥ LB condition shall be met.

### 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.

 Parameter Equation Addition of dB $${ L }_{ A }+{ L }_{ B }={ L }_{ A }+\log _{ 10 }{ (1+{ 10 }^{ \frac { -({ L }_{ A }-{ L }_{ B }) }{ 10 } }) }$$ Subtraction of dB $${ L }_{ A }-{ L }_{ B }={ L }_{ A }+\log _{ 10 }{ (1-{ 10 }^{ \frac { -({ L }_{ A }-{ L }_{ B }) }{ 10 } }) }$$