Ledenergy Savings Calculator
Use our free Ledenergy savings Calculator for quick, accurate results. Get personalized estimates with clear explanations.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Annual Savings = (Old Watts - LED Watts) x Bulbs x Hours/Year / 1000 x Rate + Bulb Replacement Savings
Calculate the annual electricity savings by multiplying the wattage difference by number of bulbs, annual usage hours, and electricity rate. Add the savings from fewer bulb replacements since LEDs last 15-50 times longer than incandescents.
Worked Examples
Example 1: Whole Home Incandescent to LED Conversion
Problem:A home has 25 incandescent bulbs (60W each, $1.00 each, 1,000-hour life). Replace with 9W LEDs ($3.00 each, 25,000-hour life). Usage: 5 hours/day at $0.15/kWh.
Solution:Old annual kWh: 60W x 25 bulbs x 1,825 hrs / 1000 = 2,737.5 kWh\nNew annual kWh: 9W x 25 bulbs x 1,825 hrs / 1000 = 410.6 kWh\nkWh saved: 2,327 kWh\nElectricity savings: 2,327 x $0.15 = $349.05/year\nOld bulb replacements: 45,625 hrs / 1,000 = 45.6 bulbs x $1.00 = $45.63/yr\nLED replacements: 45,625 hrs / 25,000 = 1.8 bulbs x $3.00 = $5.48/yr\nBulb savings: $40.15/yr\nTotal savings: $389.20/year\nUpfront cost: 25 x $3.00 = $75.00\nPayback: 2.3 months
Result:Annual savings: $389.20 | Payback: 2.3 months | 10-year net savings: $3,817
Example 2: Office CFL to LED Upgrade
Problem:An office has 50 CFL bulbs (14W, $3.00, 8,000-hour life). Replace with 9W LEDs ($4.00, 25,000-hour life). Usage: 10 hours/day at $0.12/kWh.
Solution:Old annual kWh: 14W x 50 x 3,650 hrs / 1000 = 2,555 kWh\nNew annual kWh: 9W x 50 x 3,650 hrs / 1000 = 1,642.5 kWh\nkWh saved: 912.5 kWh\nElectricity savings: 912.5 x $0.12 = $109.50/year\nOld bulb cost/yr: (182,500/8,000) x $3.00 = $68.44\nLED cost/yr: (182,500/25,000) x $4.00 = $29.20\nBulb savings: $39.24/yr\nTotal savings: $148.74/year\nUpfront: 50 x $4.00 = $200
Result:Annual savings: $148.74 | Payback: 16.1 months | 10-year net savings: $1,287
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy