What Light Bulb Wattage Do You Need?

How to Determine Safe Wattage for Light Fixtures at Home

Light bulb held in hand in front of empty light fixture

The Spruce / Leticia Almeida

Project Overview
  • Working Time: 15 mins
  • Total Time: 15 mins
  • Skill Level: Beginner

When a bulb burns out, most people grab whatever spare light bulb is available. If the old light bulb was too dim, they might opt for a higher-wattage bulb to improve the brightness. However, "lumens" measures a bulb's brightness and is what you should look to increase over watts. With incandescent bulbs, you need to increase wattage to increase brightness, but, in contrast, switching to LED bulbs will use much fewer watts than incandescent bulbs for similar or more illumination.

With many types of bulbs available, it's essential to understand the difference between bulbs, read the wattage rating on bulbs, and examine the wattage rating on light fixtures. Light fixtures carry a maximum wattage rating. If bulbs are installed that exceed this rating, there is the potential for overheating the fixture, melting the socket or electrical insulation, and causing a fire.

What Is Wattage?

Wattage is the amount of power an electrical device uses. Depending on the light bulb type, watts and lumens (brightness) vary wildly. For example, an incandescent bulb produces, on average, 14 lumens per watt, a halogen bulb emits 25 lumens per watt, a compact fluorescent produces 63 lumens per watt, and an LED creates at least 74 lumens per watt. Also, most bulbs are offered in various colors and varying degrees of whiteness—warm white to natural light to cool white.

Incandescent bulbs are the least energy-efficient and require much more wattage to achieve the same brightness as LEDs. As a base example, an LED light bulb uses 4 watts compared to an incandescent light bulb's 25 watts to reach about 250 lumens.

Comparing Bulb Types (Watts v. Lumens)

Bulb Type  Watts  Lumens
Incandescent 60 800
Compact Fluorescent Light 13-15 800
LED 8-10 800-850
Halogen 60 900-1000

The Potential Danger

Installing light bulbs with wattage ratings higher than the fixture ratings does not necessarily damage the electrical circuit wires, nor is it likely to cause a circuit breaker to trip or cause other problems to the house wiring. The potential danger usually lies in the fixture itself. Light fixtures have wire leads attached to the circuit wiring, and the heat naturally generated by a light bulb can cause these wires to overheat and possibly melt the insulation on the leads.

Some light fixtures have internal insulation to shield the wires to a specific temperature. If this temperature limit is exceeded by operating the fixture with too-large bulbs, damage to the wiring can occur. In the case of recessed light fixtures (can lights), the trapped heat can even overheat and scorch wood framing.

This potential danger exists with hard-wired light fixtures mounted in a ceiling or wall sconce and with plug-in lamps.

Before You Begin

Anytime you detect a burning odor or see scorch marks on a light fixture or lamp, it's a sign you may be exceeding the wattage rating of the light fixture. Shut off the light and turn off the power at the breaker or fuse. If it's a lamp, unplug it.

Then, look closely at the fixture. If it feels hot to the touch, that's a danger sign. At this point, it's not enough to replace the bulb with one of lower wattage—you also need to check to ensure that permanent damage hasn't already occurred.

What You'll Need

Equipment / Tools

  • Screwdriver

Materials

  • New light bulb of appropriate wattage

Instructions

How to Determine Safe Lightbulbs for Fixtures

  1. Inspect Ceiling or Wall Fixtures

    Unscrew the mounting screws, pull the light fixture away from the electrical box, and inspect the wires inside. Inspect the wire nuts or insulation on the wire leads, circuit wires, and cable sheathing. If it is melted or has scorch marks, contact an electrician for an inspection.

    Removing a light fixture from the ceiling

    The Spruce / Kevin Norris

  2. Inspect Table or Floor Lamps

    A table or floor lamp is susceptible to damage from light bulbs that are the incorrect wattage. If the shade on a lamp is hot to the touch or has become damaged by heat, the light bulb's wattage likely does not match the socket rating. If the socket is scorched, it will need to be replaced. If the wire is damaged, rewire the lamp.

    Inspecting a table lamp

    The Spruce / Letícia Almeida

  3. Find the Wattage Rating of Your Light Fixture

    The maximum wattage ratings are printed on the light-bulb sockets of the light fixture or lamp. If a fixture has two or more light bulbs, ensure the total wattage rating based on the sticker on the fixture does not exceed the maximum. It is often on the insulation or baseplate beneath the fixture's globe.

    Small sticker on light fixture with maximum wattage

    The Spruce / Leticia Almeida

  4. Understand Differences Between Incandescent, CFL, and LED

    All light bulbs, including traditional incandescent bulbs, compact fluorescent light bulbs (CFLs), or LED (light-emitting diode) bulbs, have a wattage rating printed on the glass or collar of the bulb. Most CFL or LED bulbs with standard screw-in ends can safely be used with standard light fixtures, also called Edison sockets. They are popular choices over incandescent bulbs for their energy efficiency.

    However, CFL and LED bulb packaging can sometimes be confusing because they often list their wattage equivalency to incandescent bulbs. For example, one package may say it uses only 11 watts and replaces a 75-watt light bulb. Understanding the packaging and determining the bulb's actual wattage output is essential. In this case, an 11-watt bulb is safe to use in a light fixture with a maximum socket rating of 60 watts despite the packaging that says it "replaces a 75-watt bulb."

    Tip

    LED bulbs are inexpensive, energy efficient, and long-lasting. Vast improvements have been made to address initial concerns about the quality of the light. The bulbs now produce light comparable to natural daylight, and their per-watt illumination is far better than any other type of light bulb. They are the best choice for energy conservation and go long before needing replacement, some lasting up to 12 years.

    Maximum wattage label on bottom of light bulb in fixture

    The Spruce / Leticia Almeida

  5. Screw in a Safe Bulb

    Screw in the light bulb (or bulbs) once you have confirmed the wattage will not exceed the maximum wattage rating of the light fixture.

    Warning

    CFL or LED light bulbs may emit less heat, but they can still get hot. The glass bulb is considerably cooler to the touch than standard incandescent bulbs, but the bulb base can get hot and burn an unsuspecting hand.

    Replacing the bulb in a light fixture

    The Spruce / Letí­cia Almeida

FAQ
  • Does higher wattage mean a brighter light bulb?

    Higher wattage means you get a brighter bulb when scaling up from the same bulb type. However, if you are switching types of bulbs and switching to LEDs from incandescent, the wattage may be considerably less on an LED while being a much brighter (or higher lumen) bulb.

  • What happens if I put a 75 watt bulb in a 45 watt lamp?

    Using a higher-wattage bulb in a lower-wattage lamp can cause the fixture to overheat and melt, potentially creating a fire hazard.

  • What is the LED equivalent of a 60-watt bulb?

    The LED equivalent of a 60-watt bulb is about 8 to 10 watts.