LED Lighting Savings Calculator

The fastest ROI in home energy efficiency.

Last Updated:

Usage Profile

Electricity Details

Old Cost/Yr
$328.5
LED Cost/Yr
$49.28
Annual Savings$279.23

Efficiency Fact: LED bulbs use about 75-80% less energy than traditional incandescent bulbs and last up to 25 times longer. The return on investment for a lighting upgrade is typically measured in months, not years.

Share this tool

Why Lighting is the "Low Hanging Fruit" of Energy Efficiency

Of all the energy-saving upgrades you can make to a property, none offers a faster return on investment than switching to LED (Light Emitting Diode) bulbs. While a solar installation may take 7–10 years to pay for itself, a full LED retrofit often pays back in just 4–8 months.

Wattage vs. Lumens

In the past, we bought bulbs based on Watts (how much electricity they consume). Today, we measure output in Lumens (how much light they produce).

To produce 800 lumens (the standard "daylight" brightness):

  • An Incandescent bulb uses 60 Watts.
  • A CFL (Compact Fluorescent) uses 14 Watts.
  • A modern LED uses only 8.5 to 9 Watts.

The Hidden Benefit: Heat Load

Traditional incandescent bulbs are essentially small space heaters that happen to emit light as a byproduct. About 90% of the energy they consume is released as heat. In the summer, this increases the load on your air conditioning system. By switching to LEDs, you're not just saving on the light itself; you're also reducing your cooling costs.

Longevity and Maintenance

Maintenance is often the most overlooked cost of traditional lighting.

  • Incandescent life: ~1,000 hours.
  • LED life: ~25,000 to 50,000 hours.

If you leave a light on for 5 hours a day, an incandescent bulb will burn out in 200 days. An LED will likely last for over 13 years. For commercial properties with high ceilings, the labor savings of not needing a ladder every few months often outweighs the energy savings.

Lighting Cost Formula

Watts are converted to kilowatt-hours by dividing by 1000, then multiplied by your electricity rate. Savings is the old-bulb cost minus the LED cost.

Yearly Cost = Bulbs × Watts × Hours per Day × 365 / 1000 × Rate
BulbsNumber of bulbs
WattsWattage per bulb
Hours per DayDaily usage per bulb
365Days per year
RateElectricity price per kWh

Manual Calculation Example

Compare a hypothetical home with 20 bulbs used 5 hours a day at $0.15 per kWh: 60 W incandescents versus 9 W LEDs.

1
Incandescent Cost
2,190 kWh per year at the given rate.
20 × 60 × 5 × 365 / 1000 × $0.15 = $328.50
2
LED Cost
328.5 kWh per year at the given rate.
20 × 9 × 5 × 365 / 1000 × $0.15 = $49.28
3
Yearly Savings
Old-bulb cost minus LED cost.
$328.50 − $49.28 = $279.23
4
Note
Bulb purchase prices are not included in the comparison.
Electricity only

Frequently Asked Questions

Does the calculator include the price of the bulbs?
No. It compares electricity running costs only. To find the payback period, divide the extra upfront cost of the LEDs by the yearly electricity savings.
Why is the wattage divided by 1000?
Electricity is billed in kilowatt-hours. Dividing watts by 1000 converts them to kilowatts before multiplying by hours of use.
Can I compare CFLs instead of incandescents?
Yes. Enter the CFL wattage in the old-bulb field and the LED wattage in the new-bulb field to compare any two bulb types.
Do LEDs really last longer than incandescents?
LEDs are typically rated for 25,000 to 50,000 hours versus about 1,000 hours for an incandescent, so you also save on replacements.

Formula and method

annual savings = (old watts - new watts) × fixtures × hours ÷ 1,000 × electricity price

Use actual operating hours and fixture count. Cooling savings and heating penalties from lower lamp heat are building-specific and should not be assumed without modelling.

Assumptions to check

  • Old and new lamps provide comparable useful light.
  • Operating hours are unchanged after replacement.
  • Replacement, labour, dimmer, and disposal costs are entered separately.

Worked example: replacing twenty 60 W lamps with 9 W LEDs

Twenty fixtures operate three hours daily and electricity costs $0.17/kWh.

  1. 1. Find power reduction

    (60-9)×20 = 1,020 W = 1.02 kW

    Compare actual lamp input power.

  2. 2. Find annual energy savings

    1.02×3×365 = 1,116.9 kWh

    This assumes the same daily schedule.

  3. 3. Value the savings

    1,116.9×$0.17 = $189.87

    Demand and HVAC effects are excluded.

Result: Estimated electricity savings are 1,116.9 kWh and $189.87 per year.

Frequently asked questions

Should I compare watts or lumens?

Use lumens to match light output, then compare watts for energy use. A lower-watt lamp is not equivalent if it produces much less useful light.

How do dimmers affect the estimate?

Actual power depends on dimming level, driver compatibility, and control behaviour. Use measured or manufacturer data when lights are commonly dimmed.

Does the estimate include lamp replacement savings?

Only if entered. Longer life can reduce lamp and labour costs, but rated life is not a guaranteed service life in every fixture.

About the Lighting ROI Calculator

Calculate the financial savings and exact payback period of upgrading your home's old incandescent bulbs to LEDs.

Calculator methods and editorial structure reviewed July 11, 2026. Results are estimates; verify regulated rates, eligibility rules, and professional decisions with the cited primary source.

Important: Educational Purposes OnlyThe calculators, estimates, and financial formulas provided on CalculatorVillage.com are for informational and educational purposes only. They are not intended as certified financial planning, tax, legal, or investment advice. Actual rates, terms, and returns will vary. Always consult with a qualified professional before making significant financial decisions.