Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

12 Volt - Wire Gauge vs. Amps

Maximum current (amps) in a 12V electrical circuit vs. size (AWG) and length of wire.

Conductors in electrical systems should not be sized with voltage drops exceeding 3%.

For a 12V system the maximum voltage drop should be less than (12 V) x 3% = 0.36 V.

Conductor sizes (AWG) related to maximum current through a 12V electrical copper wire and length of cable - are indicated below:

American Wire Gauge (#AWG)
Length
(feet)
Maximum Current (amps)
5101520253040506070
15 16 12 10 10 8 8 6 6 4 4
20 14 12 10 8 8 6 6 4 4 4
25 14 10 8 8 6 6 4 4 2 2
30 12 10 8 6 6 4 4 2 2 2
40 12 8 6 6 4 4 2 2 1 1/0
50 10 8 6 4 4 2 2 1 1/0 1/0
60 10 6 6 4 2 2 1 1/0 2/0 2/0
70 10 6 4 2 2 2 1/0 2/0 2/0 3/0
80 8 6 4 2 2 1 1/0 2/0 3/0 3/0
90 8 4 4 2 1 1/0 2/0 3/0 3/0 4/0

Note! Failure to use an adequate size may result in a fire. Always secure electric wires with fuses.

  • 1 ft (foot) = 0.3048 m

Wire Gauge Design Procedure

  1. calculate total length of wire from source to device and back again
  2. determine amount of current in wire
  3. determine correct wire gauge in the intersection of amps and feet

Note! Wire size based on 3% (0.36 V) voltage drop in a 12 Volt circuit. Always oversize wires if voltage drop is critical.

12 v cable length maximum amps

print 12V Cable Length Diagram

Example - 12 V Cable and Maximum Length and Current

The maximum current in a 12 Vgauge #6 (13.3 mm2) cable with length 15 m is approximately 15 amps according the diagram above.

The maximum current in a gauge #10(5.26 mm2) cable with length 15 m is approximately 5 amps.

Related Topics

  • Electrical

    Electrical engineering with units, amps and electrical wiring. Wire gauges, electrical formulas, motors and more.

Related Documents

Search

Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

Citation

This page can be cited as

  • The Engineering ToolBox (2004). 12 Volt - Wire Gauge vs. Amps. [online] Available at: https://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































4.26.8

.