Savings calculator
What could a retrofit save?
Estimate the energy, cost and carbon saved by retrofitting your existing fittings with new LED engines through reLUMEN8.
How to use it
Enter the number of fittings, the circuit watts of each existing fitting, the expected LED wattage after retrofit, annual operating hours and your electricity price. Results update instantly. Add an estimated project cost to see a simple payback.
Typical offices run lighting for 2,500–3,500 hours a year; warehouses, car parks and 24-hour spaces can exceed 6,000. A retrofit commonly cuts lighting energy by 50–70%, more when controls are added.
For a costed proposal, send us your fitting schedule. Results are estimates only.
FAQ
Calculator FAQs
How is the energy saving calculated?
Annual energy is fittings × watts per fitting × operating hours ÷ 1,000. The saving is the difference between the existing and retrofitted figures, multiplied by your electricity price.
Which carbon factor is used?
The UK government 2025 greenhouse gas conversion factor for grid electricity, 0.177 kgCO2e per kWh. You can change it to match your own reporting.
What wattage should I enter for my existing fittings?
Use the total circuit watts including control gear. As a guide, a 600×600 4×18W T8 fluorescent panel draws about 72–80W and a 2×58W T8 batten about 125–135W. A survey confirms the real figure.
How accurate is the result?
It is an estimate for budgeting. reLUMEN8 confirms actual savings from a site survey and an assessed sample fitting, and can model controls such as presence and daylight dimming.
Start a project
Send us a photo of your fittings. We'll tell you what's possible.
Book a call with a Light Engineer. Share images, location and quantities and we'll assess whether your luminaires can be retrofitted.
Enquire with 299 Lighting →