What wire gauge should I use for my landscape-lighting run?

Dear Trying,

Start with distance and load, not the number printed biggest on the spool. Smaller gauge numbers mean thicker wire, and thicker wire carries low-voltage power with less loss over a long run.

For a short branch with a modest fixture load, 14-gauge cable can be perfectly sensible. For a longer branch, more fixtures, or a route you expect to expand, 12-gauge is often the calmer choice. It costs more up front, but it gives the far end a better chance of looking like the beginning. Our wire-gauge guide walks through those tradeoffs without treating every yard as identical.

Sketch the transformer, fixture count, wattages, and approximate cable route before buying. Then compare the likely voltage drop. A route that looks like 100 feet on a patio plan can become much longer once it follows beds, steps, and sensible service paths. The wire-gauge calculator can help you test both sizes.

If you are torn, buy for the system you are building rather than the smallest version of it today. You do not need to oversize everything out of fear, but a little capacity is friendlier than reopening a finished bed later. Good wire is not glamorous. Neither is digging the same trench twice.

— Ray