Plan your low-voltage landscape lighting system. Calculate voltage drop per wire run, transformer load, and wire gauge recommendations to ensure every fixture operates at full brightness.
Transformer
Wire runs / zones
Zone nameFixturesWatts eaRun length (ft)
+ Add wire run / zone
Wire gauge
Please add at least one wire run with fixtures.
0W
Total load
0%
Transformer used
0
Total fixtures
Transformer load
Load
0%
NEC requires max 80% load on transformer. Above 80% risks overheating and tripped breakers.
Wire run analysis
ZoneLoadV dropV at endStatus
Transformer capacity
Total connected load
Load percentage
Wire gauge selected
Max run length at this gauge
Transformer remaining capacity
Landscape lighting design tips
->Load transformer to 75% max. NEC allows 80% but leaving 75% headroom protects the transformer and allows future expansion.
->Use 12 AWG wire for all runs over 50ft. 14 AWG works for short runs but voltage drop becomes noticeable beyond 50ft with multiple fixtures.
->Hub wiring reduces voltage drop. Running one heavy cable to a central hub then short spurs to each fixture keeps voltage drop minimal on all fixtures.
->LED fixtures are forgiving. Unlike halogen, most LED landscape lights work fine down to 10.8V. Check your fixture spec sheet for minimum operating voltage.
->Set transformer to 12.5V for long runs. Many transformers have multiple tap settings. Using 12.5V or 13V compensates for voltage drop on longer runs.
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