ClueLuma

Annual lamp replacements calculator

Annualizes lamp use by average life; fractional lamps are a cost estimate.

Nreplace=Nlamps×HLifeN_{\text{replace}} = \frac{N_{\text{lamps}} \times H}{\text{Life}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

lamp
h
h/yr
lamp/yr

Worked example

Given

  • NlampsN_{\text{lamps}} = 100 lamp
  • Life\text{Life} = 12,000 h
  • HH = 4,000 h/yr
Nreplace=100×400012,000≈33.333N_{\text{replace}} = \frac{100 \times 4000}{12{,}000} \approx 33.333

Symbols and units

SymbolMeaningUnit
NreplaceN_{\text{replace}}annual replacement countlamp/yr
NlampsN_{\text{lamps}}installed lampslamp
Life\text{Life}average lamp lifeh
HHannual useh/yr

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Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.