Amplifier Power Calculator

Calculate the amplifier power needed to achieve a target SPL at a given distance, accounting for speaker sensitivity and headroom.

Results

Visualization

How It Works

SPL at distance: SPL = sensitivity + 10·log10(watts) - 20·log10(distance). Every doubling of distance costs 6 dB (requiring 4× power). Every 3 dB increase needs double the power. Headroom (typically 6-10 dB) accounts for peaks and transients — music has a 10-20 dB crest factor. A speaker at 87 dB/W/m needs 100W to hit 107 dB at 1m, but 1,600W at 4m. More efficient speakers (>93 dB) dramatically reduce amplifier requirements.