LED vs Incandescent Bulbs: True Cost Comparison Over 10 Years

The Numbers Don't Lie: Year-by-Year 10-Year Cost Breakdown

The LED vs incandescent cost debate ends the moment you run the actual numbers. Using the U.S. Energy Information Administration's Q3 2025 national average electricity rate of $0.163/kWh and 3 hours of daily use, here is what each bulb type costs you — cumulative — every year for a decade.

Assumptions: 800 lumens output (standard "60W equivalent"). LED: 9W, $2.00 per bulb, 25,000-hour rated life (one bulb covers the entire 10-year period). Incandescent: 60W, $1.00 per bulb, 1,000-hour rated life — at 3 hours/day that is 333 days per bulb, meaning you buy roughly 11 bulbs over 10 years.

The math is unambiguous. By year 10, the LED has cost $13.70 total — $2.00 for the bulb itself plus $11.70 in electricity. The incandescent has cost $69.49 — $11.00 in replacement bulbs plus $58.49 in electricity. Per the Consumer Federation of America, that $55.79 per-bulb difference is entirely preventable waste. Across a whole house, it is thousands of dollars.

Note: the LED cost line flattens after year 7 because the single bulb purchased at the start is still running. The incandescent line continues to climb because you are replacing bulbs continuously. At 3 hours/day, each incandescent lasts about 11 months — so you buy a new one every year, plus the ones that fail early.

Use our LED Savings Calculator to run these numbers against your actual daily usage hours and local electricity rate.

The Full Comparison: Bulb Cost, Energy, and Replacement

Per the U.S. Department of Energy, LEDs use at least 75% less energy than incandescent lighting and last up to 25 times longer. Here is what that means in concrete numbers across all three major lighting technologies, normalized to 800 lumens (the brightness of a standard 60W incandescent) and 10 years of operation at 3 hours/day.

The DOE's 75% efficiency figure is the baseline — LEDs like the 9W example above actually achieve 85% energy reduction vs incandescent. CFL lands in the middle: far better than incandescent but still 2x the operating cost of LED. With CFL bulbs now phased out from most retail shelves, LED is the clear and only rational choice.

Want to factor in your specific appliances and usage patterns? Our Appliance Energy Calculator breaks down electricity costs for every device in your home.

Why Incandescent Bulbs Are 5x More Expensive

The physics of incandescent lighting explains the cost gap completely. When electricity passes through an incandescent filament, the filament heats to roughly 2,700°C and glows. But the vast majority of that energy radiates as infrared heat, not visible light. A standard 60W incandescent produces only about 6 watts of actual visible light — efficiency of roughly 10%. The other 54 watts become heat, per basic thermodynamic measurement of the technology.

This is not a manufacturing defect — it is inherent to how incandescent bulbs work. There is no version of a hot-filament bulb that is efficient. Every optimization attempt over 130 years has hit the same physical ceiling.

The Replacement Treadmill

Incandescent bulbs are rated at 1,000 hours. At 3 hours of daily use, that is 333 days — just under a year. So over 10 years, each socket needs roughly 11 bulbs. At $1.00 each, that is $11.00 in bulb purchases alone, before a single watt of electricity is counted. In practice, failure rates are uneven — some bulbs fail in the first 200 hours, others last 1,200. But the average holds at roughly 1,000 hours, meaning the replacement cost is real and predictable.

An LED rated at 25,000 hours at 3 hours/day lasts 22.8 years. You buy one bulb, install it, and do not think about it again for over two decades. Zero replacement trips to the hardware store. Zero burned-out bulbs at inconvenient times.

The Electricity Math

Per the U.S. Energy Information Administration (EIA) Q3 2025 data, the national average residential electricity price is $0.1663/kWh. A 60W incandescent running 3 hours/day consumes 65.7 kWh/year. At $0.163/kWh, that is $10.71/year in electricity per bulb. A 9W LED running the same schedule consumes 9.9 kWh/year — $1.61/year. The annual savings per bulb: $9.10. Over 10 years: $91.00 in electricity savings per socket, more than covering the entire LED vs incandescent cost difference and then some.

Whole-Home 10-Year Savings Calculator

Individual bulb savings are meaningful. Whole-home savings are transformative. The Consumer Federation of America data shows that households with 20 or more bulbs save over $1,000 in a decade by switching to LED. Here is what that looks like across different home sizes, using the same $0.163/kWh rate and 3 hours/day per bulb.

The 10-year savings column includes both electricity savings and avoided bulb replacement costs. At 30 bulbs, you avoid buying roughly 330 incandescent replacements ($330) while also saving $1,347 on electricity — for a combined $1,677 over the decade. That is the cost of a new appliance, a vacation, or a significant home improvement, generated passively just by changing your light bulbs.

For a personalized projection based on your home's actual bulb count and usage patterns, use our LED Savings Calculator. It accounts for mixed usage times across different rooms and lets you input your actual electricity rate.

For context on how lighting compares to your other high-draw appliances, see our guide on what uses the most electricity in a home.

Beyond the Bulb: The Hidden HVAC Cost

The electricity and bulb replacement math already makes the LED case airtight. But there is a third savings stream that almost no comparison includes: reduced air conditioning load.

As established above, a 60W incandescent converts 54W into heat. That heat enters your living space. If you have air conditioning running — which in the U.S. means roughly 5 to 8 months of the year for most of the population — your AC system has to remove that heat. Running 30 incandescent bulbs simultaneously generates 1,620W (1.62 kW) of continuous heat load. That is comparable to running a small space heater in your living room.

A 9W LED generates approximately 4W of waste heat per bulb — compared to 54W for an incandescent, that is a 93% reduction in heat output. Thirty LEDs produce only 120W of heat total, versus 1,620W from thirty incandescents. The difference — 1,500W of continuous heat load eliminated — directly reduces the work your air conditioner has to do.

What This Saves in Real Money

A typical central air conditioner removes heat at roughly 3.5 kWh of electricity per 12,000 BTU removed (a COP of about 3.5 for a modern unit). 1,500W of continuous incandescent heat load running 3 hours/day translates to roughly 4.5 kWh of heat added per day during those operating hours. Your AC must expend approximately 1.3 kWh to remove that heat. At $0.163/kWh over a 5-month cooling season, that is $31.60 per year in AC electricity purely attributable to your incandescent lighting.

In hot climates — Texas, Arizona, Florida, the Gulf Coast — where cooling runs 7-8 months per year and peak temperatures are higher, that figure climbs to $50-$100 annually. Add this to the direct electricity savings and you're looking at payback under three weeks in warm-climate homes.

For a full analysis of where your home's electricity goes and where the biggest savings opportunities are, read our guide on home energy savings tips.

How to Read LED Packaging: Lumens, Kelvin, CRI

LED packaging has standardized significantly over the past five years, but it still confuses shoppers accustomed to simply buying a "60 watt bulb." Here is what every number on the box actually means — and which ones matter.

Shop by Lumens, Not Watts

Watts measure energy consumption, not brightness. Lumens measure the actual light output. The wattage on an LED tells you how efficient it is; the lumens tell you how bright it is. For replacing incandescent bulbs:

• 450 lumens replaces a 40W incandescent
• 800 lumens replaces a 60W incandescent
• 1,100 lumens replaces a 75W incandescent
• 1,600 lumens replaces a 100W incandescent

Most LED packaging now includes a "replaces X watt" line to simplify this — but knowing the lumen equivalents lets you compare across brands accurately.

Color Temperature (Kelvin Scale)

Kelvin (K) describes the color of the light, not its intensity. Lower numbers are warmer and more yellow; higher numbers are cooler and bluer.

• 2700K (Soft White): Warm, yellowish glow — identical to traditional incandescent. Best for living rooms, bedrooms, and dining rooms. This is the default recommendation if you are replacing incandescents and want no perceptible difference in ambiance.
• 3000K (Warm White): Slightly crisper than 2700K, still warm-toned. Excellent for kitchens and bathrooms where task visibility matters but warmth is still wanted.
• 4000K (Cool White / Neutral): Clean, neutral light. Ideal for home offices, laundry rooms, garages, and task lighting where accuracy and alertness matter more than ambiance.
• 5000K+ (Daylight): Bright, blue-white. Best for workshops, utility spaces, and reading lamps. Feels clinical in living spaces — use intentionally.

CRI: Color Rendering Index

CRI measures how accurately a light source renders colors compared to natural daylight, on a scale of 0-100. Incandescent bulbs score 100 — perfect rendering. Early LEDs were infamous for their poor CRI (70-75), making everything look washed out or slightly wrong. Modern LEDs have solved this problem.

For living spaces — kitchens, bathrooms, closets, dining rooms — look for CRI 90 or higher. The difference between CRI 80 and CRI 92 is visible and significant: food looks more appetizing, clothing colors are accurate, skin tones are more natural. For hallways, closets, and utility areas, CRI 80+ is perfectly adequate and costs less.

ENERGY STAR Certification

According to the DOE's ENERGY STAR program, certified LEDs must meet strict efficiency, light output, color quality, and lifespan standards — and manufacturers must back those ratings with testing data. Per ENERGY STAR certification requirements, certified bulbs must maintain at least 70% of their initial light output after 25,000 hours of operation (the L70 standard). This is the most reliable shortcut for identifying quality LEDs: if it carries the ENERGY STAR mark, the performance claims are verified.

Dimmable Labeling

Not all LEDs are dimmable. Non-dimmable LEDs used on a dimmer switch will flicker, buzz, or fail early. Always check the packaging explicitly for "dimmable" before purchasing for any fixture on a dimmer circuit. If your existing dimmer switches are more than 10 years old, they may also need replacement — older leading-edge (TRIAC) dimmers designed for incandescent minimum loads of 40W-60W do not work properly with LEDs drawing 9W-12W. LED-compatible trailing-edge dimmers cost $15-$30 and are widely available.

For a deeper dive into energy-efficient lighting strategy and fixture-by-fixture optimization, see our complete energy-efficient lighting guide. For a broader electricity reduction strategy, read how to reduce your electricity bill.

Frequently Asked Questions