light bulb savings calculations

these calculations display your estimated savings based on assumptions below

for customized calculations enter your own data in the green fields

Wattage
9 watts
Rated Lifetime
25,000 hours
price
$4.95
average incandescant (INC) light bulb
Wattage
watts
Rated Lifetime
hours
price

cost per kilowatt hour
bulb use per day hours

how your savings are calculated

step 1 find the number of INC bulbs needed over this bulb's lifetime

25000 / 750 = 33.3333

step 2 determine the cost of replacement INC bulbs and the difference with this bulb's cost

33.3333 * $0.50 = $16.67 cost of replacing the INC bulb

$16.67 - $4.95 = $11.72 replacement savings

step 3 determine energy usage over the life of this bulb

60 watts * 25000 hours / 1000 watts per kW = 1500 kWh

9 watts * 25000 hours / 1000 watts per kW = 225 kWh

step 4 subtract to find the difference in energy usage between the bulbs

1500 kWh - 225 kWh = 1275 kWh lifetime savings

step 5 find the lifetime energy cost savings

1275 kWh * $0.118 = $150.45

step 6 combine energy savings with replacement cost savings to find total lifetime savings

$150.45 + $11.72 = $162.17 total lifetime savings

step 7 find savings per year

5 hours per day * 365 days per year = 1825 hours per year

1825 hours per year / 25000 lifetime hours = 7.30 % of bulb life used per year

7.30 % * 1275 kWh lifetime savings = 93.075 kWh yearly savings

7.30 % * $162.17 lifetime savings = $11.84 yearly savings

Savings calculations are presented as an example of potential savings; actual savings may vary based on use, utility rates and other factors. Calculations are based on national averages and assumptions and may be adjusted for a more accurate estimate of individual savings. While EnergyEarth strives to provide the most accurate information, we cannot guarantee the savings displayed.