AWG 14 carrying 20 A — 3.31 V over 10 m
2.081 mm² of copper, 0.00827 Ω per metre. Carrying 20 A, a ten-metre run there and back loses 3.31 V.
You need thicker wire · Current it handles 14.8A
- Diameter
- 1.628 mm
- Cross-section
- 2.081 mm²
- Resistance per metre
- 0.00827 Ω
- Current it handles
- 14.8 A
- Drop over 10 m
- 3.31 V
- Heat per metre
- 3.31 W
Length within 3%
Lose the same 0.36 V and it is 3% of a 12 V system but 0.16% of a 230 V one. That is why car wiring looks so thick, and why a long 12 V light run dims at the far end. This page works out the length that stays under 3% for each voltage separately.
- car 12 V1.1 m
- truck 24 V2.2 m
- North America 120 V10.9 m
- Europe 230 V20.9 m
The match in the other family
The United States names wire by AWG number; most of the world names it by cross-section in mm². The two never line up exactly, so each page shows the nearest match by area. When substituting, err toward the thicker one.
2.5mm²2.5mm²Nearby cells
Same gauge, other currents
Same current, other gauges
How to read this
- The length is the distance from source to device. The return trip is already counted.
- Figures are for copper. Aluminium of the same size has about 1.6 times the resistance.
- The "current it handles" is a cautious estimate. Real installations follow the local code table.
- A wire running hot and a lamp dimming at the far end are two different problems. Pick a gauge that answers both.
Frequently asked questions
Q. Can AWG 14 carry 20 A?
No. This gauge tops out around 14.8 A, so step up to something thicker.
Q. How far can I run it?
The drop stays under 3% for 20.9 m at 230 V, 10.9 m at 120 V, or 1.1 m at 12 V.
Q. How many mm² is AWG 14?
2.081 mm², from a diameter of 1.628 mm. The nearest size in the other family is 2.5mm².
Q. How hot does the wire get?
Every metre turns 3.31 W into heat. Over ten metres that is a 33.1 W heater left running.