Landscape Lighting Transformer Calculator
Estimate a preliminary low-voltage landscape-lighting transformer size, load utilization, annual energy use and transformer planning cost.
Default project preview
150 W
Fixture connected load
108 W
Total connected load
108 W
Loss-adjusted load
118.8 W
Selected-load utilization
79.2%
Calculator
Build the material order
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Enter the project details and calculate a rounded material estimate.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Connected load = fixture count × watts per fixture + other load. Loss and spare-capacity allowances are applied, then the result is rounded up to a common transformer size.
FAQ
Landscape Lighting Transformer Calculator questions
Why include cable and driver losses?+
The transformer supplies more than the fixture nameplate load because wiring and electronic components consume some power.
Why add spare capacity?+
A reserve allows modest future fixture additions and keeps the transformer from being planned at its exact calculated demand.
Does transformer wattage solve voltage drop?+
No. Voltage drop also depends on cable gauge, current, run length, branching and transformer taps.