Wiring inside cabinets typically ranges from 0.5 mm² for low-voltage LED lighting to 2.5 mm² or larger for standard 120V appliance circuits.

Low-Voltage Cabinet Wiring

For under-cabinet LED lighting or accent lighting, low-voltage wires are commonly used. These wires are thin and flexible, often in the range of 0.5 mm² to 1.0 mm², which is sufficient to carry the small currents required by 12V or 24V LED systems while remaining easy to conceal along cabinet edges . The cross-sectional area in mm² determines the current-carrying capacity, not just the wire diameter, so even small wires can safely power low-voltage lighting.

High-Voltage Appliance Wiring

For standard 120V or 240V circuits inside cabinets, such as for microwaves, coffee stations, or built-in appliances, the wiring must handle higher currents. Typical sizes include 1.5 mm² to 2.5 mm² for general-purpose circuits, with larger sizes used for high-power appliances . These wires are usually NM-B (Romex) or similar, and must be clamped and routed to avoid sharp edges or abrasion inside the cabinet.

Wire Sizing Considerations

• Cross-sectional area (mm²) is the key factor for current capacity; doubling the mm² roughly doubles the current the wire can safely carry .
• Solid vs stranded conductors: Stranded wires may have slightly less effective copper area due to air gaps, so check the nominal mm² rating .
• Code compliance: Ensure wiring meets local electrical codes, including GFCI protection for kitchen circuits .
• Conversion from AWG: If using American Wire Gauge, 14 AWG ≈ 2.08 mm² and 12 AWG ≈ 3.31 mm² .

Practical Recommendation

• LED lighting: 0.5–1.0 mm²
• Small appliance circuits: 1.5–2.5 mm²
• High-power appliances: 4 mm² or more, depending on amperage Selecting the correct mm² ensures safety, efficiency, and compliance while maintaining a neat installation inside the cabinet.