Headphone Power Calculator

Adjust the calculator values below

Headphone impedance Use the nominal impedance stated by the headphone manufacturer. Sensitivity reference Choose the same reference printed on the headphone specification; dB SPL/mW and dB SPL/V are not interchangeable. Sensitivity at 1 mW (dB SPL) Target sound pressure level This is an electrical capability target, not a safe listening recommendation; high sound levels can damage hearing. Result power unit Result voltage unit Result current unit

Compare with an amplifier Amplifier power at this headphone impedance Use the amplifier's rated output into the same or a closely matching headphone impedance. Amplifier output impedance The source gives headphone impedance divided by eight as a rule-of-thumb upper limit.

Required RMS voltage 0.566 V RMS

Required average power 10 mW

Required RMS current 17.678 mA RMS

Headphone impedance 32 ohm

Sensitivity at 1 mW 100 dB SPL

Sensitivity at 1 V RMS 114.949 dB SPL

Target sound pressure level 110 dB SPL

Level increase above 1 mW sensitivity 10 dB

Amplifier power at headphone impedance 100 mW

Maximum modeled SPL from amplifier power 120 dB SPL

Amplifier power margin 90 mW

Amplifier headroom 10 dB

Power compatibility Meets target with 10 dB modeled headroom

Amplifier output impedance 1 ohm

Rule-of-thumb maximum output impedance 4 ohm

Impedance ratio 32:1

Output-impedance check Within the one-eighth rule-of-thumb limit

Listening safety note Required electrical capability is not a safe listening-level recommendation

Model assumption Resistive nominal impedance at the sensitivity test frequency

0.566 V RMS

Required RMS voltage 32 ohm, 100 dB SPL at 1 mW, and 110 dB SPL target

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Headphone Power Calculator

Calculate headphone power, RMS voltage, current, converted sensitivity, amplifier headroom, and output-impedance compatibility.

Enter only independent headphone specifications

Use nominal impedance, one manufacturer sensitivity rating, and a target sound-pressure level. The calculator converts the selected sensitivity reference and derives power, RMS voltage, and RMS current. This avoids asking for several dependent electrical values as though they were independent inputs.

Convert sensitivity and calculate electrical demand

Sensitivity at 1 milliwatt equals sensitivity at 1 volt plus 10 times log base 10 of impedance divided by 1000. Required power in milliwatts is 10 raised to the target-minus-sensitivity difference divided by 10. RMS voltage is the square root of power in watts times impedance, and RMS current is voltage divided by impedance.

Compare amplifier power at the same load

An amplifier power rating is meaningful only at a stated load impedance. The optional check compares rated amplifier power at the entered headphone impedance with required average power, estimates SPL headroom from the power ratio, and checks output impedance against the headphone-impedance-divided-by-eight rule of thumb.

Separate capability from safe listening

A target SPL describes modeled output capability, not a recommended continuous listening level. High sound levels can damage hearing, and real program peaks, duration, seal, frequency response, calibration, and individual susceptibility matter. Use conservative volume settings and appropriate hearing-safety guidance.

Understand the nominal-impedance model

Real headphone impedance and sensitivity vary with frequency, and amplifier voltage, current, distortion, protection, gain, and clipping limits can prevent ideal output. Manufacturer ratings may use different test frequencies and conventions. Confirm measurements and specifications for the exact headphone-amplifier pairing.

Frequently asked questions

Common questions about headphone impedance, sensitivity references, required power, RMS voltage and current, amplifier headroom, and listening safety.

How is required headphone power calculated?

Subtract sensitivity in dB SPL at 1 milliwatt from the target SPL, divide by 10, and raise 10 to that power. The result is required average power in milliwatts.

How do I convert dB SPL at 1 volt to dB SPL at 1 milliwatt?

Add 10 times log base 10 of headphone impedance divided by 1000 to the 1-volt sensitivity. The calculator performs this conversion after impedance and the correct sensitivity reference are selected.

How are required voltage and current calculated?

Convert required power to watts, then take the square root of power times impedance for RMS voltage. Divide RMS voltage by impedance for RMS current, using the nominal resistive-load approximation.

How should I compare an amplifier power rating?

Use the amplifier's power rating at the same headphone impedance, or the nearest documented load with appropriate caution. A wattage quoted at a different impedance does not prove the same voltage, current, distortion, or clipping performance.

What is the one-eighth output-impedance rule?

It is a rule of thumb that amplifier output impedance should be no more than one eighth of headphone impedance. A lower output impedance generally reduces frequency-response interaction with changing headphone impedance, but it is not the only compatibility criterion.

Does the target SPL mean that level is safe to listen to?

No. The result estimates electrical capability, not a safe continuous volume. Hearing risk depends on sound level, exposure duration, program content, fit, calibration, and individual factors, so use conservative volume and appropriate hearing-safety guidance.