Decibel Calculator
Add or subtract incoherent dB levels and predict SPL at a new distance.
Add / subtract dB
83.01 dB
A + B
— dB
A − B
SPL at distance
80 dB
Predicted SPL
About this tool
Add or subtract two sound levels in decibels (incoherent / RMS sum) and apply the inverse-square distance law to predict SPL at a different distance from a point source.