LED vs. Incandescent: What the Energy Numbers Actually Mean for Your Home

Wattage vs. Lumens: Understanding What You're Actually Buying

One of the most persistent sources of confusion when switching bulb types is conflating wattage with brightness. Wattage measures how much electrical power a bulb consumes — it says nothing about how much light it produces. Lumens measure light output. A 60-watt incandescent and a 9-watt LED can both produce roughly 800 lumens of light; the LED simply does it using about 85% less electricity.

This distinction matters when you're shopping. Instead of looking for a "60-watt replacement," look for the lumen count on the package. For general living spaces, 800 lumens is a common reference point. For task lighting like a kitchen counter, you may want 1,000 lumens or more. For a bedside table, 450–500 lumens is often sufficient.

Understanding this also helps you decode your electricity bill, where your total consumption is measured in kilowatt-hours (kWh) — a unit that reflects wattage over time, not brightness.

The Real Cost of Running Each Bulb Type

Let's ground the numbers in a realistic household scenario. Assume you have a lamp used four hours per day, 365 days a year — that's 1,460 hours of annual use. At a U.S. average electricity rate of around $0.16 per kWh (rates vary significantly by region and over time — check your own bill for accuracy):

• A 60-watt incandescent consumes 87.6 kWh per year → roughly $14 annually per bulb.
• A 9-watt LED consumes 13.1 kWh per year → roughly $2.10 annually per bulb.

That's approximately $12 in savings per bulb, per year. Multiply that across 20 light fixtures in a typical home, and the annual saving potential is substantial — without changing any behavior, just the bulb type. For a deeper look at how lighting fits into your home's overall energy picture, see how your home's three biggest energy systems compare.

Lifespan: Why Replacement Frequency Changes the Equation

An incandescent bulb typically lasts around 1,000 hours. At our four-hours-per-day example, that's less than nine months before it needs replacing. A quality LED, by contrast, is typically rated for 15,000 to 25,000 hours — meaning the same bulb could last over 17 years under the same usage pattern.

This lifespan gap means the upfront price difference between an LED and an incandescent is almost never an apples-to-apples comparison. Over the life of a single LED, you might buy 15 to 25 incandescent replacements. When bulb purchase costs and energy costs are combined, LEDs consistently come out ahead — usually within the first one to two years of use.

Once you've made the switch, the next question is choosing the right LED for each space. Our guide to LED lighting by room — colour temperature, lumens, and placement walks through exactly that.

Where to Prioritize Your Switch

Not every bulb in your home offers the same return. Focus your first replacements where lights run the longest each day:

1. Kitchen and living areas — these are typically lit for 4–8 hours daily and offer the highest per-bulb savings.
2. Outdoor security and porch lights — often left on all night, making them disproportionately expensive with incandescents.
3. Bathroom vanity fixtures — multiple bulbs in a single fixture multiplies the impact of switching.

Low-priority candidates include infrequently used spaces like garages, attics, or storage rooms where lights may run fewer than 30 minutes a day — the payback period is longer and the urgency lower.

Lighting is just one part of a broader efficiency picture. If you're evaluating where to invest next, a complete walkthrough of your home's major energy systems can help you prioritize systematically.