LED Savings Calculator
See exactly how much you'll save by replacing old bulbs with LEDs — plus how fast the upgrade pays for itself.
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Why LED bulbs save so much
LED bulbs use 75–85% less electricity than incandescent bulbs to produce the same amount of light. A 60W incandescent bulb can be replaced by a 9W LED that looks identical. The LED also lasts 10–25 years instead of 1–2 years for incandescent.
This is one of the few home upgrades where the payback is measured in months, not years. The upfront cost is now low ($2–$4 per bulb in multipacks), and the savings are immediate and permanent. If you're still using incandescent or halogen bulbs anywhere in your home, replacing them is the single fastest energy change you can make.
How we calculate this
Formula: (old watts − new watts) × bulb count × hours × 365 ÷ 1000 × rate = annual savings.
Example: 20 incandescent bulbs at 60W replaced with 9W LEDs, 4 hours per day, $0.14/kWh.
- Watts saved per bulb: 60 − 9 = 51W
- Total watts saved: 51 × 20 = 1,020W
- Daily watt-hours saved: 1,020 × 4 = 4,080 Wh
- Annual watt-hours saved: 4,080 × 365 = 1,489,200 Wh
- Convert to kWh: 1,489,200 ÷ 1000 = 1,489 kWh
- Annual savings: 1,489 × $0.14 = $208.46 per year
- Upfront cost: 20 × $3.50 = $70
- Payback: $70 ÷ $208 = 0.34 years = about 4 months
That's a real number, and it's typical. Most homes see payback in 4–8 months depending on how many hours the bulbs are on.
Typical LED replacements
- 60W incandescent → 9W LED — 800 lumens, warm white (2700K)
- 75W incandescent → 11W LED — 1100 lumens, soft white (3000K)
- 100W incandescent → 14W LED — 1600 lumens, cool white (4000K)
- 50W halogen → 6W LED — 450 lumens, warm white
Full guide: How to Choose the Right LED Bulbs.
What affects the actual savings
Three things move the number up or down:
- Hours of use: A bulb that's on 8 hours a day saves twice as much as one on 4 hours. Kitchen and living room bulbs save the most.
- Your electricity rate: If you pay $0.25/kWh (California, Hawaii), savings nearly double compared to $0.14/kWh.
- Bulb wattage: Replacing a 100W incandescent with a 14W LED saves more than replacing a 60W with a 9W.
Payback time is affected by the LED price. At $2/bulb (multipack), payback can be under 3 months. At $5/bulb (premium brand), it might be 8–10 months. Either way, the LED pays back within the first year.
Sources and methodology
LED wattage equivalents come from the U.S. Department of Energy's Lighting Facts program (Energy.gov) and manufacturer specifications from major brands (Philips, Cree, GE, Sylvania). The 75–85% efficiency range is based on DOE's comparison of LED versus incandescent technologies. Electricity rates use the U.S. EIA 2024 average of about $0.17/kWh. Our calculator uses the standard kWh formula shown in every utility bill, and we've tested the results against real bill data.
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Frequently Asked Questions
Are LEDs really worth the higher upfront cost?
Yes. Even though they cost more per bulb ($2–$5 vs. $0.50 for incandescent), they last 10–25 years and use 75–85% less electricity. Payback is measured in months, and every year after the first is pure savings.
Do LEDs really last 10+ years?
Yes, but with a caveat. The 10–25 year lifespan is for standard household use (4 hours per day). If a bulb is on 12 hours a day, expect 4–8 years. Heat also shortens LED lifespan — avoid using them in enclosed fixtures unless the packaging says they're rated for it.
Will LEDs work in my old fixtures?
Mostly yes. LEDs come in all standard bases (E26, E12, GU10, etc.). The main exceptions are dimmer switches (some older dimmers cause flickering with LEDs — see our guide) and very enclosed fixtures (which can overheat LEDs).
Do I need to replace every bulb at once?
No. Start with the bulbs that are on the most hours per day — kitchen, living room, home office. Replace bedrooms and hallways later. Even one room's worth of LEDs saves meaningful money.
What about the environmental impact?
LEDs use less energy, which means less fossil fuel burned at power plants. They also contain no mercury (unlike CFLs). The main concern is that LEDs contain small amounts of rare earth elements, but the energy saved over their lifetime far outweighs the manufacturing impact.