Choosing the Right Wire Gauge for Landscape Lighting

Why Wire Gauge Matters in Outdoor Lighting

Wire gauge — the thickness of the copper wire used to connect your fixtures — plays a critical role in how well your lighting system performs. In low-voltage (12V) systems, even small mistakes in wire size can lead to major problems, especially across long runs.

Using the wrong wire gauge is one of the most common mistakes we see in Central Florida systems installed by handymen, landscapers, and budget contractors.

The Basics of Wire Gauge

Wire gauge is measured in AWG (American Wire Gauge). The lower the number, the thicker the wire:

  • 12 AWG – Most common for professional systems

  • 10 AWG – Extra-heavy-duty; used for long or high-load runs

  • 14–16 AWG – Too thin for most outdoor applications; often found in DIY kits

  • 18 AWG or smaller – Practically useless for anything beyond 10 feet

Thinner wire = more resistance = more voltage loss. And that means dimmer lights, uneven performance, and early failures.

Read our Voltage Drop Article

Common Wire Gauge Mistakes (And Why We Fix Them)

Mistake #1 – Using Undersized Wire to Save Money

We’ve seen entire systems run with 16 or 18 AWG wire — the kind you'd find in cheap solar kits. It’s cheap up front, but it can’t carry power more than a few feet without significant voltage drop.

The result? Flickering, dimming, and early fixture failure.

Mistake #2 – Long Runs with No Gauge Adjustment

Even good fixtures will perform poorly if they’re at the end of a 150-foot run of 12 AWG wire with 10+ lights on it. At Ecotek, we calculate wire length and load, and size up to 10 AWG when needed to ensure brightness stays consistent.

Mistake #3 – No Plan for Expansion or Load Balancing

Wire gauge should match not only today’s load — but tomorrow’s too. When you add lights without upgrading your wire, you risk overloading the system. We leave margin and run wire layouts with growth in mind.

How We Choose Wire Gauge at Ecotek


We don’t guess — we calculate. Every job gets a wire plan based on:

  • Fixture VA load

  • Distance from transformer to final fixture

  • Acceptable voltage drop range (usually aiming for 10.8–11.5V at end)

  • Transformer tap voltage (12V–15V+)

  • Run layout (hub, T, loop, daisy chain)

Typical Specs:

  • 12 AWG for standard runs

  • 10 AWG for long or high-load branches

  • Gel-filled waterproof connections for corrosion resistance

  • Proper burial depth and protection from mower/trimmer damage

Read Our Transformer Size Article

Read About Our Maintenance Package

Signs Your System Has Wire Gauge Issues

  • Lights are noticeably dim on one side of the property

  • Lights flicker or fade out as the night goes on

  • Transformer runs hot or shuts off intermittently

  • New lights cause older ones to act up

  • Some zones perform well while others struggle

Cheap Wire = Expensive Repairs


Undersized wire isn’t just a performance issue — it’s a financial liability. Fixing it often requires trenching, rerouting, and rewiring large sections of your property.

That’s why we only use high-quality, properly sized wire from day one — and leave capacity for future upgrades.

Want a Lighting System That’s Wired to Last?

We install low-voltage systems across Central Florida using the right gauge wire, voltage-balanced layouts, and proper connections that keep your lighting performing year after year — not just for one season.

Learn About Our Lighting Packages

Learn About Us

Contact Us

No Guesswork. No Undersized Wire. No Redos.

Let’s get it right the first time — with wire that delivers clean, consistent power across your entire system.

Contact Us

Need help design a great landscape lighting system for your home? Fill out the form below, and one of our representatives will be in touch for the next steps!