Lighting ROI Calculator

Calculate Payback for
LED Lighting
with costs & interest

Please read: This calculator gives payback time, and both the annual and life-time cost & savings figures for energy, maintenance, and CO2 production.  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 for lower than 90% Power Factor.  Calculator will not perform properly if removed from this site. 

Power of long-term Leasing or Financing
brought by the Return from Savings.

  Select entry with mouse, enter and step w/ Tab key.
Step back with Shift + Tab.
      If residential lighting, enter 95 for PF (Power Factor).

  Parameters for energy statistics:  
Simple Comparison Options
(Not photometric)         



LPD (Lighting Power Density) = Watts ÷ Sq-Ft
 Sq-Ft per Fixture =  Total
Target LED LPD =  fixtures  
LPD Statistics      W/Sq Ft
Original LPD      
new  LED LPD      
=  Saved      
Click for suggested LPD (see that Table 1)
  Enter:  Power Consumption, Power Factor, & No. of Fixtures
Orig. W  & PF % LED W Quantity 
 Totals:          Cost  $/ kWhr  
Hours/Day  ×   Days/Wk  ×   Weeks/Yr 
Annual Energy Cost: Original
Savings:    Annual = $     Monthly = $         %
Fuel:  Coal  Gas   Petrol   Hydro  Nuclear   
  Results:  Payback time, Return On Investment, Savings, Cost & Interest: 
CO2 reductions
 Tons Less / year
 Tons Less / lifetime

  Cookie Jar 

    Annual Savings:
  Investment ÷ (Energy + Maint. Savings)
                 $ ÷ $  =  Year Payback 
Simple ROI (energy & maint. saved−Investment) ÷ Investment = % 
           Annual ROI:            LED to Original cost:  
  Payments:  (Payback)   Max     $
    LED Investment: (LED maintenance is cleaning, inspection, etc. as should be done with all lighting.)  
  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:  
   Original fixture life  Hours ÷  Hours/Year  =  Years Lifetime     $ Full Cost for 1 Fixture Installed  
Years × $ annual energy cost = $  Relamp Cost  $(relamping, disposal, cleaning, etc. every  years)
 $  + $ energy = $  Orig. Cost during LED Lifetime, repaired  times.
 *US national average CO2 emissions caused by various power generation capabilities, value provided by the US EPA. 
            Home             ©2011-2014 Patrick Mullins     Please Contact me with any comments regarding this calculator.