14 AWG to mm²
14 AWG is the gauge most camper electricians default to for branch circuits in the 5–15 A range. It handles interior LED lighting, USB outlets, small fans, and 12V cigarette sockets without breaking a sweat. Below 14 AWG you are into signal-wire territory (16 / 18 AWG); above it (12 AWG) is for water pumps, vent fans, and small motor loads. In standard metric cable, 14 AWG corresponds to 1.5 mm² — the most stocked size in European auto-electrical and marine shops.
All values on this page assume copper conductors at 20°C ambient. Aluminum has ~60% higher resistance for the same cross-section and is generally not recommended for low-voltage DC.
Calculate for your specific cable run
The tables below assume 14 AWG (1.5 mm²) copper. Use the calculator to confirm this gauge is correct for your exact load and length, or get a different gauge recommendation if needed.
= 60W
= 16.4 ft (one way, round-trip calculated automatically)
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Download Cable for iOS14 AWG Voltage Drop at 12V DC
Round-trip voltage drop for 14 AWG (1.5 mm²) copper wire at 20°C ambient. Cells highlighted in yellow exceed the 3% target; red cells exceed 5% and are not recommended.
| Current | 1 m / 3 ft | 2 m / 7 ft | 3 m / 10 ft | 5 m / 16 ft | 7 m / 23 ft |
|---|---|---|---|---|---|
| 2 A | 0.048 V (0.40%) | 0.095 V (0.79%) | 0.14 V (1.19%) | 0.24 V (1.98%) | 0.33 V (2.78%) |
| 5 A | 0.12 V (0.99%) | 0.24 V (1.98%) | 0.36 V (2.98%) | 0.60 V (4.96%) | 0.83 V (6.94%) |
| 8 A | 0.19 V (1.59%) | 0.38 V (3.17%) | 0.57 V (4.76%) | 0.95 V (7.93%) | 1.33 V (11.11%) |
| 10 A | 0.24 V (1.98%) | 0.48 V (3.97%) | 0.71 V (5.95%) | 1.19 V (9.92%) | 1.67 V (13.88%) |
| 12 A | 0.29 V (2.38%) | 0.57 V (4.76%) | 0.86 V (7.14%) | 1.43 V (11.90%) | 2.00 V (16.66%) |
| 15 A | 0.36 V (2.98%) | 0.71 V (5.95%) | 1.07 V (8.93%) | 1.79 V (14.88%) | 2.50 V (20.83%) |
14 AWG Voltage Drop at 24V DC
Round-trip voltage drop for 14 AWG (1.5 mm²) copper wire at 20°C ambient. Cells highlighted in yellow exceed the 3% target; red cells exceed 5% and are not recommended.
| Current | 1 m / 3 ft | 2 m / 7 ft | 3 m / 10 ft | 5 m / 16 ft | 7 m / 23 ft |
|---|---|---|---|---|---|
| 2 A | 0.048 V (0.20%) | 0.095 V (0.40%) | 0.14 V (0.60%) | 0.24 V (0.99%) | 0.33 V (1.39%) |
| 5 A | 0.12 V (0.50%) | 0.24 V (0.99%) | 0.36 V (1.49%) | 0.60 V (2.48%) | 0.83 V (3.47%) |
| 8 A | 0.19 V (0.79%) | 0.38 V (1.59%) | 0.57 V (2.38%) | 0.95 V (3.97%) | 1.33 V (5.55%) |
| 10 A | 0.24 V (0.99%) | 0.48 V (1.98%) | 0.71 V (2.98%) | 1.19 V (4.96%) | 1.67 V (6.94%) |
| 12 A | 0.29 V (1.19%) | 0.57 V (2.38%) | 0.86 V (3.57%) | 1.43 V (5.95%) | 2.00 V (8.33%) |
| 15 A | 0.36 V (1.49%) | 0.71 V (2.98%) | 1.07 V (4.46%) | 1.79 V (7.44%) | 2.50 V (10.41%) |
What is 14 AWG (1.5 mm²) used for?
Camper / RV applications
- LED interior lighting circuits (typically 2–5 A total)
- Vent fans (Maxxair, Fiamma) up to 6 A
- USB outlets and 12V cigarette sockets
- Small water pumps under 7 A continuous
- Control circuits to relays, switches, dimmers
Boat / marine applications
- Navigation and anchor lights
- Cabin LED lighting
- Instrument panel feeds and GPS plotters
- Small bilge pumps under 12 A
- Stereo head unit and cabin USB outlets
Off-grid / solar applications
- Branch circuits in tiny homes and cabins
- Lighting circuits in garden sheds and workshops
- Sensor and monitoring system feeds
- Small fan and ventilation circuits
When to step up
- Continuous current above 12 A — within 20% of ampacity
- Cable runs longer than 4 m at 12V with currents above 8 A
- Water pumps with inrush above 15 A (use 12 AWG to absorb the spike)
- Anything with a motor: motor inrush is 3–5x continuous current
Fuse size for 14 AWG (1.5 mm²)
The fuse must protect the wire, not the load. For 14 AWG copper (1.5 mm²) the maximum fuse rating is 15 A. Below this ceiling, size the fuse at 125% of your continuous load current and round up to the next standard fuse size.
| Continuous Load | 125% Calculation | Recommended Fuse | Fuse Type |
|---|---|---|---|
| 2 A | 2.5 A | 5 A | Blade (ATC) |
| 5 A | 6.25 A | 7.5 A | Blade (ATC) |
| 8 A | 10 A | 10 A | Blade (ATC) |
| 10 A | 12.5 A | 15 A | Blade (ATC) |
| 12 A | 15 A | 15 A | Blade (ATC) |
Related conversions
Frequently Asked Questions
What is 14 AWG in mm²?
14 AWG is precisely 2.08 mm² by the IEC formula. In standard metric cable, 14 AWG is sold as 1.5 mm² — the closest stocked size below the precise value. The VoltPlan calculator uses 1.5 mm² (15 A ampacity) as the metric equivalent of 14 AWG.
Is 14 AWG enough for 12V LED lighting?
Yes, comfortably. A typical camper interior pulls 2–5 A on its lighting circuit; 14 AWG is rated for 15 A and easily handles this load with under 1% voltage drop on cable runs up to 5 m. You can even daisy-chain ~4 lighting branches before needing to step up to 12 AWG.
Can I use 14 AWG for a 12V water pump?
Depends on the pump. Most camper water pumps (Shurflo 4008, Whale Universal) draw 5–7 A continuously and 15–20 A at startup inrush. The 15 A ampacity of 14 AWG is right at the inrush limit, so 12 AWG (25 A) is the safer choice. Use 14 AWG only for small pressure pumps under 5 A continuous.
What size fuse for 14 AWG wire?
Use a 15 A blade fuse (ATC/ATO) to protect 14 AWG wire. If your continuous load is below 12 A, size the fuse at 125% of load and round up — for example a 5 A load takes a 7.5 A fuse. Never exceed 15 A on 14 AWG.
How long can 14 AWG run at 12V before voltage drop is a problem?
At 12V with a 3% voltage drop target, 14 AWG handles 5 A over ~7.5 m, 10 A over ~3.7 m, and 15 A over ~2.5 m. Lighting circuits at 2–3 A can stretch much further (15 m+). For everything above 10 A, step up to 12 AWG once runs exceed 4 m.