Estimate costs, cuts, and payback
LED Energy Savings Calculator
Lift the space, cut the costs—estimate your LED savings.
LED Energy Savings Calculator
Estimate annual energy, cost savings, COâ‚‚ reductions and payback from upgrading legacy lighting to modern LED.
Tip: toggle units; we’ll convert automatically.
hrs/day
days/week
weeks/year
Advanced assumptions
UK grid varies by year; 0.20–0.25 kg/kWh is common for estimates.
Using ft²
Current system
– kWh / yr
£– per year
– kg CO₂ / yr
Selected LED
– kWh / yr
£– per year
– kg CO₂ / yr
Annual savings
£–
– kWh | –%
– kg CO₂
Connected load (W/m²)
Current: –
LED: –
Total project cost (opt.)
£0
Based on £/m² input
Simple payback
–
Capex ÷ annual savings
This is an estimate for guidance only. For a detailed survey and proposal, contact Root3 Lighting.
FAQ’s
Here are the key facts behind the calculator—how we estimate energy, costs, CO₂ and payback—so you know exactly what’s driving your results.
How does the calculator work?
We estimate energy use from your lighting power density (W/m²) × lit floor area × operating hours. Presets for fluorescent/metal halide/older LED are compared with modern LED options, and (optionally) smart controls that add an extra percentage reduction. Costs are based on your tariff (£/kWh) and CO₂ is calculated using a grid factor (kg/kWh). You can enter area in ft² or m²—there’s a built-in unit toggle.
What inputs should I use for area, hours and tariff?
Area: use the lit floor area (exclude plant rooms if unlit).
Hours: typical offices run ~10 h/day, 5 days/week, 50 weeks/year; warehouses/retail may be higher—use your best average.
Tariff: take the latest £/kWh from your energy bill or contract. If unsure, start at £0.25/kWh. CO₂ factor of 0.20–0.25 kg/kWh is common for the UK grid.
Hours: typical offices run ~10 h/day, 5 days/week, 50 weeks/year; warehouses/retail may be higher—use your best average.
Tariff: take the latest £/kWh from your energy bill or contract. If unsure, start at £0.25/kWh. CO₂ factor of 0.20–0.25 kg/kWh is common for the UK grid.
How accurate are the results?
The tool gives a directional estimate for planning and budgeting. Actual savings depend on fittings, mounting heights, light levels, daylight availability, occupancy patterns, maintenance factors, and controls commissioning. For firm numbers we’ll perform a site survey, lighting design, and a fixed proposal.
How do payback and ROI get calculated?
Enter an optional project cost in £/m². We multiply by your area to estimate CAPEX, then divide by the annual cost saving:
Simple payback = CAPEX ÷ yearly saving. For a full ROI (NPV/IRR) including maintenance and funding options, request a survey and proposal from Root3.Still have more questions?
Prefer a tailored quote? Speak to a lighting engineer. We offer a free lighting survey.
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