How much do LED bulbs save per year?

Replacing 25 incandescent 60W bulbs with 9W LEDs saves about 1,277 kWh per year at 5 hours/day usage. At $0.15/kWh, that's $191/year savings. For a fully incandescent home, LED upgrades typically save $100-$400/year depending on fixture count and usage.

How long does it take for LED bulbs to pay back?

LED bulbs typically pay back their cost in 1-4 months when replacing incandescent bulbs in frequently used fixtures. The higher your electricity rate and the more hours your lights run, the faster the payback. LEDs then save money for 15-25 years — their typical lifespan.

LED Lighting Calculator

Calculate your savings from switching to LED — annual kWh reduction, cost savings, and payback period on your LED investment.

Lighting setup

Number of fixtures?

bulbs

Old bulb wattage?

W each

New LED wattage?

W each

Hours on per day?

hrs/day

Electricity rate?

$/kWh

LED cost per bulb?

LED savings — 85% reduction in lighting wattage

Save $349/year — 2,327 kWh/year

Monthly savings$28.69/mo

Old monthly cost$33.75/mo

LED investment$125

Payback period4.4 months

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How to Use This Calculator

Count your fixtures and current wattage

Walk through your home and count all light bulbs and fixtures. Enter the total number of fixtures and the wattage of your current bulbs. Common old bulb wattages: incandescent 40W, 60W, 75W, 100W; CFL 13W (40W equiv), 18W (60W equiv), 23W (75W equiv); T8 fluorescent tube 32W.

Enter the LED replacement wattage

LED equivalents use about 85% less energy than incandescent for the same light output. Common LED wattages: 60W-equivalent LED = 8-10W; 100W-equivalent LED = 14-16W; candelabra (25W equiv) = 4W; T8 LED tube = 12-15W. Check the "equivalent to" wattage on the LED packaging.

Set usage hours and LED cost

Enter the average hours your lights run per day — for a typical house, 4-6 hours/day is common. The LED cost per bulb is used to calculate your investment payback period. Budget LEDs cost $2-4; quality dimmable LEDs run $8-15.

The Formula

Old daily kWh = Fixtures × Old watts × Hours/day ÷ 1,000 New daily kWh = Fixtures × LED watts × Hours/day ÷ 1,000 Daily savings kWh = Old kWh − New kWh Annual savings kWh = Daily savings × 365 Annual savings ($) = Annual kWh savings × Electricity rate LED investment = Fixtures × Cost per LED Payback (months) = LED investment ÷ Monthly savings ($)

This calculator models the scenario of replacing all fixtures at once. In practice, many households replace bulbs as they burn out. To model that, calculate for just the remaining incandescent count. LEDs last 15,000-25,000 hours (10-25 years at 5 hrs/day) — you'll likely never need to replace them again.

Example

Average US home — 25 fixtures switching to LED

A homeowner has 25 incandescent 60W bulbs used an average of 5 hours per day. They replace all with 9W LEDs at $5 each, paying $0.15/kWh.

Fixtures25 bulbs

Old wattage60W incandescent

New LED wattage9W (60W equiv)

Hours per day5 hrs

LED investment$125 (25 × $5)

Result

Old lighting cost$101.25/month

New LED cost$15.19/month

Monthly savings$86.06/month

Annual savings$1,032/year

Payback period1.5 months

The LED upgrade pays back in just 6 weeks and saves over $1,000 every year afterward. This is one of the highest-ROI efficiency upgrades available — better than most solar installations in pure payback terms.

FAQ

How much does switching to LED reduce electricity bills? ▼

Replacing all incandescent bulbs with LEDs typically reduces your total home electricity bill by 10-20%, since lighting represents 10-15% of average US home electricity use. The savings are larger if you have many lights or use them frequently. Replacing just the most-used 5 lights saves as much energy as replacing 30 seldom-used ones.

Do LED bulbs reduce heat generation? ▼

Yes — and this creates a hidden additional saving in summer. An incandescent bulb wastes 90% of its energy as heat. In air-conditioned spaces, this means your AC works harder to remove the heat your lights produce. Switching 25 incandescent 60W bulbs to 9W LEDs reduces heat generation by ~1,275W — which your air conditioner no longer needs to remove. In hot climates with significant cooling load, the total energy saving from LEDs can be 15-20% more than the direct electricity saving alone.

What is the best LED bulb to buy? ▼

Look for ENERGY STAR certified LED bulbs — they are tested for light output, efficiency, and lifespan. Key specs: lumens (light output, not watts), color temperature (2700K = warm white, 5000K = daylight), CRI (color rendering index, 80+ for home use), and dimmable rating if needed. Brands like Cree, GE, and Philips Hue offer reliable options. For frequently used fixtures, buy quality — cheap LEDs sometimes flicker, have inconsistent color, or fail early.

How many solar panels would it take to power LED lights? ▼

After switching to LED, 25 lights at 9W each running 5 hours/day use 1.125 kWh/day. A single 400W solar panel produces about 1.55 kWh/day on average. So just one solar panel can power all your home lighting after an LED upgrade — before the upgrade, you'd need 7 panels for the same load. This illustrates why efficiency upgrades and solar work so well together.