Headphone Amp Calculator — Power Requirements

Low-impedance headphones (16-32Ω) are often loud enough from a phone or laptop. High-impedance headphones (250-600Ω) almost always need a dedicated amp to reach satisfying volume and dynamics. The real issue is usually voltage, not raw wattage.

The output impedance of your amp should be no more than 1/8th of your headphone impedance for a flat frequency response. For 32Ω headphones, the amp output impedance should be below 4Ω. Higher output impedance can alter the sound.

Crest factor is the difference between peak and average signal levels, typically 10-12 dB for music. Your amp needs to handle peaks without clipping. A 10 dB crest factor means your amp needs 10 times the average power for clean peaks.

Sensitivity (dB/mW) tells you how loud the headphones get per milliwatt of power. Higher sensitivity = louder at the same power. Impedance affects how much voltage and current the amp needs to deliver that power. High impedance needs more voltage, low impedance needs more current.