How much power do my headphones need?

It depends on sensitivity and target volume. Most efficient headphones (100+ dB/mW) need less than 10mW for comfortable listening at 85 dB. For peak levels of 110 dB with 100 dB/mW sensitivity, you need 10mW. Planar magnetics with 85 dB/mW sensitivity may need 300+ mW for the same level.

Is voltage or current more important for headphones?

High-impedance headphones (250-600 ohms) need more voltage but less current. Low-impedance headphones (16-32 ohms) need less voltage but more current. This is why high-impedance headphones pair well with valve amps (high voltage) while low-impedance headphones suit portable devices (limited voltage).

What SPL level should I target?

Average listening at 75-85 dB SPL is safe for extended periods. Musical peaks can reach 100-110 dB. Audiologists recommend limiting exposure to 85 dB for 8 hours, 94 dB for 1 hour, or 100 dB for 15 minutes. The WHO recommends keeping daily exposure below 85 dB.

Can a phone drive high-impedance headphones?

Most phones output about 1V maximum into high impedance. For 300-ohm headphones at 100 dB/mW sensitivity, 1V gives about 103 dB — enough for most listening. But headroom for peaks may be limited. A dedicated amplifier is recommended for headphones above 150 ohms.

AudioCalcs

Headphone Power Calculator — Voltage & Current Requirements

Calculate power and voltage needed to drive headphones to a target SPL.

Sensitivity

Impedance

Target SPL

How We Calculate This

Power Requirement

Power (mW) = 10^((Target SPL − Sensitivity) / 10)

Where sensitivity is in dB/mW. Each +10 dB requires 10× more power.

Voltage Requirement

Voltage (V) = sqrt(Power × Impedance)

Current Requirement

Current (mA) = Voltage / Impedance × 1000

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.