Acoustics / Physics

Decibel Calculator

Convert between decibels and intensity ratios. Calculate sound pressure levels and compare noise sources.

Convert dB ↔ Ratio

Decibels (dB)

Intensity Ratio (I/I₀)

Sound Level Reference

Combined Sound Levels

Add multiple dB sources together (e.g. two speakers, multiple machines)

L_dB = 10 log₁₀(I/I₀) · I₀ = 10⁻¹² W/m² (threshold of hearing)
+3 dB = double intensity · +10 dB = 10× intensity · +20 dB = 100×