Amplifier Sizing Calculator

A freeware Windows calculator for

sound system designers

Win XP, 7, 8, 10

1. Select the amplifier sine wave rating using the Amp Level slider.


2. Determine the RMS voltage output using the Signal Crest Factor selector.


3. Select the loudspeaker's average sensitivity using the Avg. Sens. slider.


4. Select the axial listener distance using the Distance slider.


5. Read peak or RMS SPL on the meter. RMS is "slow" response.


6. Re-adjust amplifier size to target SPL on meter.


- Note the RMS voltage to the loudspeaker on the Voltmeter.

- Note the Watts to Ldspk next to the sound level meter.

- Note the gain above reference sensitivity next to the sound level meter.


Note: Steps can be done in any order.

WireCalc allows you to quickly determine the required wire gauge depending on the load impedance and cable length.


It is accessed from the Tools box of AmpCalc.

Video Tutorials

AmpliCalc Overview by Pat Brown