The math behind wire combinations and why cross-sectional area matters.

When you do not have the exact wire gauge in your workshop inventory, you must substitute it. The golden rule of substitution is that you match the cross-sectional area (measured in square millimeters, mm²), not the diameter.

Cross-sectional area dictates how much current a wire can safely carry. To calculate the area of a round wire, use the formula Area = π × (Diameter / 2)². For example, a wire with a 1.0mm diameter has an area of roughly 0.785 mm².

By using tools like GaugeArea, you can find combinations of multiple smaller wires (e.g., three wires of 0.3mm²) that equal the target area of your original large wire. This keeps the total current capacity perfectly balanced.