This chart from Blue Seas is a nice chart to figure out 12 Volt DC wire size based on amps, length and acceptable voltage drop. (If your system is 24 volt, use 1/2 the round trip distance for looking up acceptable gauge)
ADDED 4/23/2020:
ADDED 4/23/2020:
- Downloadable Chart
Click here for a PDF download of the chart: http://assets.bluesea.com/files/resources/reference/20010.pdf
Note that the chart is for 12V. See the fine print about this near the top of the download. - Circuit Wizzard Calculator
For other voltages you can use the BlueSeas circuit wizzard here: http://circuitwizard.bluesea.com/ - Blue Seas Web site
To go to the Blue Seas web page, click on the orange "Got to download" button in the upper right of this screen or click here: https://www.bluesea.com/resources/1437 (The page does not say it, but the chart shown is for 12V. For 24V, cut the round trip wire length in half in order to look up the acceptable Gauge)
