What Bulb For
Your answer

Can you use a 60 watt LED in a 40 watt fixture?

Yes, if the watts it actually uses are within the fixture’s limit. An LED sold as a 60 watt equivalent gives an old 60 watt bulb’s light on far fewer watts, such as the 8.8 watts of Feit’s OM60DM/927CA.

watts
watts

If the fixture has no limit marked, use a bulb of 60 watts or less, or 25 watts in an unmarked ceiling fixture with miniature bulbs.

Within the limit?

It’s within the limit

The bulb uses 9 W, and the fixture allows up to 40 W.

  • Compare the watts under Energy Used on the Lighting Facts label. Ignore the “equivalent” watts on the front of the box.
  • If the limit is for the whole fixture, add up the Energy Used of all its bulbs.
  • Turn the power off and let the old bulb cool before you change it.

Which watts count

Two watt figures sit on an LED’s box. The equivalent, such as “60 watt replacement”, names the old bulb whose light it matches. Energy Used, on the Lighting Facts label, is what the bulb draws, and that’s the figure the fixture’s limit is about.

When the fixture lists an LED limit

Some fixtures give a separate, lower limit for LEDs. Williams-Sonoma’s Encalmo table lamp allows a 60 watt incandescent or the 9 watt LED bulb it comes with, and Broan’s 765H80L fan light takes only an A19 LED up to 14 watts. Where a fixture lists one, the LED’s Energy Used has to stay within that limit.

Why the limit is there

A bulb of higher wattage than recommended may overheat the fixture, its wiring or nearby things that can burn, and lead to a fire. Incandescent bulbs release 90% of their energy as heat.

Need the lumens instead?

Watts to lumens

Common questions

Does a fixture's max wattage apply to LED bulbs?

Yes. The limit is in watts, so compare it with the LED's Energy Used, or with the fixture's own LED limit if it lists one.

Can I put a 100 watt equivalent LED in a 60 watt fixture?

Yes, if its Energy Used is 60 watts or less and the fixture lists no lower limit for LEDs.

Where we get our information from

The label wording comes from the FTC’s labeling rule, the fixture limits from the CPSC and Philips (Signify), the heat figure from ENERGY STAR (EPA), and the bulbs and fixtures from their makers’ own pages and instructions. Checked against published data from FTC, ENERGY STAR, Signify, CPSC and Feit Electric (plus 2 more).

See all 7 sources
  • FTC Appliance Labeling Rule, 16 CFR 305.23: the Lighting Facts label (brightness, yearly cost, life, light appearance, energy used, mercury; 3-way levels)
  • ENERGY STAR (EPA), “Learn About LED Lighting”: heat and LED life
  • Philips Lighting (Signify), Lamp Specification Guide 2015: shape codes, color rendering, color names, safety notes
  • US Consumer Product Safety Commission, Home Electrical Safety Checklist (Pub 513): bulb wattage for the fixture
  • Feit Electric product page: 8.8W (60W Replacement) Soft White (2700K) A19 E26 Base Dimmable LED (OM60DM/927CA/4)
  • Broan-NuTone fan and light pages and installation guides: 750 (100 W light, 7 W night light), QT130LE (10 W GU24 LED, 4 W C7 night light), 765H80L (A19 E26 LED up to 14 W) and AE80LK (integrated LED module)
  • Williams-Sonoma, Encalmo Globe Table Lamp assembly instructions: rated wattage by bulb type, shade size and spacing

General guidance from manufacturer and standards data. Products vary, so check the label and the maker's instructions.