LED bulb wattage equivalents: replace brightness, not watts

Incandescent shoppers learned to use watts as shorthand for brightness because similar bulbs converted electricity to light in similar ways. LEDs break that relationship: two bulbs can use different watts and still produce similar light.

The package number to compare is lumens. DOE guidance uses roughly 450 lumens for a traditional 40W replacement, 800 for 60W, 1,100 for 75W and 1,600 for 100W. Product ranges vary, so use those as shopping anchors rather than promises.

Read the old bulb label if it is still legible, then record the fixture type and whether the bulb is dimmed or enclosed. Choose a replacement near the same lumen output and with the correct base and shape.

For a fixture with several bulbs, compare total lumens. Four 800-lumen lamps produce a very different result from four 450-lumen lamps even if both packages say they replace a familiar incandescent wattage.

Savings depend on the difference between existing and replacement wattage, hours used and electricity price. A high-use kitchen or exterior fixture usually deserves attention before a closet lamp that runs only minutes per day.

Use the calculator with your actual fixture count and rate. That separates a satisfying lighting upgrade from one with a meaningful financial payback.