What is the maximum wattage on 18 gauge speaker wire?

Answer 1

Voltage is not related to gauge. Gauge of wire is related to current.

Actually, its better to say, " current capacity ", which is the carrying capacity
of metallic wire" as in the " quantity " of electron flow per second .

Think of ( voltage ) as water pressure.
house( 60lbs/sq ft ), car wash( 1600lbs/sq ft )
Think of how much water is flowing ( current ).
to fill the bucket per time.
the dam outflow at the reservoir per time.
Think of the valve as ( resistance ) to flow.
the faucet changes pressure and flow rate.
the dam gate changes pressure and flow rate.
the tub shower head( soft or massage ).

the equation ( E = I x R ) which is

( Electromotive Force = Intensity x Resistance ... restated becomes )

( Volts( pressure ) = Current( flow ) x Resistance( slow down ) )


Shuffle on carpet to the door knob ... ZAP(3-4 thousand volts).
However add more "quantity" of electrons( .5 Current (Amps)) and your
nervous system overloads, and your heart stops.
A light bulb. 120volts AC( pressure EMF ) and
60W( watts )
Watt represents ( Pressure x Intensity ).
AC means, "alternating current", eg. take a pendulum (magnetized) and
swing it over a piece of wire (copper), magnetism will push the copper
electrons first one way then the other (back).
A car battery. 12 volts DC, is not an alternating - push ( NS SN ) current flow.
In batteries (chemical) the flow is only one way, from positive to negative.
Just like a garden hose one direction. From hi potential to neutralization.
A car tire, has air pressure, a valve, push it and the air comes out fast
then slower, slower til neutralized to the atmospheric pressure being
whatever sea level or mountain level. Not just electronics. <<>>

Wire insulation

The first thing we have to do is clarify between the two items. The wire's voltage rating is an insulation rating of the wire. Like wire with ratings of 300 volts, 600 volts and 1000 volts these are the highest allowable voltages that can be applied. A wire that is rated for 300 volts is good for 120 volts, 240 volts and 277 volts. At test research facilities, equipment is tested to destruction. The label that is given to wire as a result of the tests is the highest safest voltages that can be applied to that particular wire. So when you see a wire that has a label stating that it is rated for 300 volts it means that any voltage under and up to 300 volts is safe to apply. The ability of a wire to carry current (amps) is related to the diameter size of the wire.
To answer this question, a #18 copper conductor with an insulation factor of 90 degrees C is rated at 6 amps.

Answer 2

The maximum wattage for 18 gauge speaker wire will depend on the length of the wire and the impedance of the speakers. As a general rule of thumb, 18 gauge wire can typically handle between 50-100 watts for short runs (less than 50 feet) with 8 ohm speakers. It's best to consult the wire manufacturer's specifications or use a wire gauge calculator to determine the appropriate wattage for your specific setup.