Lighting ROI Calculator

Find Payback
in costs & maint.
with LED Lighting

Please read: This calculator gives payback time, and both the annual and life-time cost & savings figures for energy and maintenance.  It calculates Lighting Power Density from area of at least 500 square feet per fixture, and provides the maximum fixtures allowed from a target LPD.  Check the DOE for your requirement.  Non-residential electric usually has additional cost if lower than 90% Power Factor.
Calculator will not perform properly if removed from this site.
Go to Graphics Version
      Comparisons        Compare CO2        Show LPD        Cookies
 Select Enter Power Factor (PF) 95 for residential.
Fuel:  Coal   Petroleum
Natural Gas   Hydro   Nuclear
CO2 Reduction from original by lower power consumption.

 Metric Tons Less / year
 Metric Tons Less / lifetime
Simple Comparisons
(Not photometric)


  Cookie Jar  

Parameters for Calculations:  
 Enter:  Power (W),  Power Factor (PF),  Quantity & Time On
Original W  & PF % LED W Quantity 
 Totals:          Electricity $/kWh
Time On:  Hours/Day  ×   Days/Wk  ×   Weeks/Yr 
Annual Energy Cost: Original
Basic Energy Savings:  Annual = $     Monthly = $    (%)
LPD (Lighting Power Density)
 SqFt / Fixture =  Total
Target LPD =  fixtures  
LPD Statistics      W/SqFt
Original LPD      
new  LED LPD      
=  Saved      
See Table 1 Here

Results:  Payback time, ROI, Equipment Savings, Cost & Interest
 Annual Savings:  
Investment ÷ (Energy + Maint. Savings) = $ ÷ $  =  Year Payback
Simple ROI(saved energy & maint. −Investment) ÷ Investment = %
Annual ROI:           LED to Original cost:  
   Payment Count Choice:  by savings, or,      by selection.
 (define Lease or Finance program)     ≈ $
LED Investment:
LED Life  Hours ÷   Hours/Year  =  Years Lifetime
       Saves $ Energy
Full Installed Cost – Discounts for; 1 Fixture = $  Interest 
LED Maintenance Interval:  years @ $ per visit 
     [Lifetime ÷ Interval × Cost × Quan.] = $
 ($ × ) + $ = $  + FIXED JOB COSTS $ = $ Investment
Subtract a rebate from FIXED JOB COSTS, or,
enter negative (-)JOB COSTS if rebate only.
Original fixture with lifetime maintenance and energy costs:
 $ One Fixture Installed
Lamp life  Hours ÷  Hrs use per year =  Years Lifetime 
LED Project Years × $ original annual energy = $
 Relamp = $(relamping, disposal, cleaning, etc. every  years)
Original Cost with repair  times during LED Lifetime:
$ + $ energy + $
*US national average CO2 emissions caused by various power generation values provided by the US EPA.
Home         ©2011-2015 Patrick Mullins     Please Contact me with any comments regarding this calculator.