What Your Pool Light Costs to Run: Incandescent vs LED

Most pool owners have never actually calculated what their pool light costs to run. It is one bulb, how bad can it be? The answer depends entirely on which era of bulb is behind that lens. A 500W incandescent and a modern LED doing the same job differ by roughly a factor of ten, and over a swim season that gap turns into real money. Here is the math, laid out so you can plug in your own numbers.

The Formula

Electricity cost is watts, hours, and your utility rate:

Side by Side, One Season

Using 4 hours a night, a 180 night season, and $0.15 per kWh:

That is roughly $49 versus $540 over ten years for the 500W case, on electricity alone. Run the light more than four hours, keep the pool open year round like many Florida owners do, or pay more than $0.15 per kWh, and the gap widens further.

The Costs the Table Leaves Out

The electricity is only half the incandescent bill. Flood bulbs and lens gasket kits typically run $40 to $80 together and tend to be needed every one to three seasons. If a pool service does the swap, add a service call each time. And every reseal carries some risk of a leak that ruins the whole fixture. The LED replacement removes all of those line items at once, because it is a sealed unit rated for 50,000 hours with no bulb and no gasket to maintain. The full comparison, including the hardware cycle, is in Pool Light Burned Out? Replace It with LED Instead of Another Bulb.