Wire Size Calculator

This marine electronics wire size calculator calculates the cross-sectional area of wire required to carry a set maximum current over a defined distance with various derating factors applied for temperature and location.

🔌 Wire Sizing Calculator

Current (A):

Total Circuit Length (m):

Note: The total circuit length must include the total length of both conductors.

System Voltage (V):

Allowable Voltage Drop:

As a guide use the following:

1% - used for charging circuits, some sensitive control circuits.
3% - Bilge pumps, sensitive electronics, lighting.
10% - Non-critical, high current, heavy duty loads

Insulation Temperature Rating (°C):

Ambient Temperature (°C):

Number of Wires in Bundle:

Installed in Engine Room

As always you are warned to use this at your own risk and with due regard to local rules, regulations and exact circumstances. If in doubt ask a pro.