Car Subwoofer Wire Gauge Calculator

Determine the correct wire gauge for your car subwoofer installation to minimize voltage drop and maximize performance.

Recommended Wire Gauge

-- AWG
Formulas & Notes
  • Current (I) in Amps: I = Power / Voltage
  • Voltage Drop (V): Vdrop = 2 × Length × I × R_per_foot
  • Choose wire gauge (AWG) so that Vdrop ≤ Maximum Acceptable Voltage Drop.
  • Use copper wire values for R_per_foot.
  • Shorter wire or higher gauge reduces voltage drop and improves subwoofer output.

How to Use

  • Enter your amplifier’s RMS power in watts.
  • Enter the one-way wire length from amplifier to subwoofer.
  • Enter system voltage (12V or 24V depending on car setup).
  • Set the maximum acceptable voltage drop (recommended 3-5%).
  • The calculator will show the proper AWG wire gauge to use.

Who Can Use

  • Car audio installers
  • DIY car audio enthusiasts
  • Professional subwoofer system designers

Where to Use

  • Single subwoofer installations
  • Multiple subwoofers in parallel or series
  • Car or marine audio systems
  • Custom amplifier-subwoofer setups

FAQs

Wire gauge (AWG) represents the thickness of the wire. Thicker wire (smaller AWG number) carries more current with less voltage drop.

Yes, but longer wires require thicker gauge to prevent excessive voltage drop.

You should use a thicker wire (lower AWG number) or reduce wire length to keep voltage drop within acceptable limits.
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