Homelab - Building Services
Light replacement calculator
Enter tariff from your power bill and up to 5 light replacement scenarios including old and new wattage (after replacement), number of globes and daily usage in hours/day. Press Calculate button to show results.
You can add or change the data and recalculate to see the difference.
 

 
Tariff (c/kWh)
Old wattage New wattage Qty Hrs/day Savings ($/year)
1
2
3
4
5
Total
This light replacement calculator is indicative only, and should not be solely relied upon as a complete calculation tool for any rebates or savings. Homelab accepts no responsibility for errors or miscalculations of this calculator. The results may not be accurate as some input data depends on correct estimation.
 
The table below shows typical light replacement options, with before and after wattages. The wattages are quoted on like-for-like basis, that is, the new light should produce same or marginally higher light output.

 
 Product
Old wattage
New (LED) wattage
 Incandescent globes

75W or 100W

10W or 12W
 Down lights

35W or 50W

6W
 Fluoro tubes  600mm

18W

7W-9W
 Fluoro tubes 1200mm

36W

12W
 High bays

400W

100W

 Shop lights - rectangular

75W or 150W

18W or 24W
 Shop lights - round

2 x 26W

15W