Lighting ROI Calculator

Calculate the savings from replacing old bulbs with energy-efficient LEDs.

General Inputs
Scenario 1
Scenario 2
Total Cost Projection

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Frequently Asked Questions

LED bulbs use about 80-90%% less energy than traditional incandescent bulbs and 50%% less than halogen bulbs. For a single 60W bulb replaced by an 8W LED, you save about 52 kWh per year (assuming 3h/day usage).

Yes, significantly. A typical LED lasts 15,000 to 25,000 hours, whereas an incandescent bulb lasts about 1,000 hours. This reduces both waste and the long-term cost of buying replacements.

Brightness is measured in lumens. A traditional 60W bulb produces about 800 lumens. When buying an LED, look for the lumen rating (approx. 800lm) rather than the wattage to ensure the same light level.

For bulbs that are on for more than 2 hours a day (like living room or kitchen lights), the electricity savings usually pay for the new LED bulb within 6 to 12 months, making it a very high-ROI upgrade.

This refers to the color temperature (measured in Kelvin). Warm White (~2700K) is similar to traditional bulbs and feels cozy. Cool White (~4000K) is brighter and better for task-oriented areas like offices or garages.

Usually, yes. LEDs use about 80-90%% less energy than incandescent bulbs. For a bulb that is on for several hours a day, the electricity savings often pay for the new LED bulb within 6 to 12 months.

A typical LED lasts 15,000 to 25,000 hours, whereas an incandescent bulb only lasts about 1,000 hours. This means far fewer replacements and less waste over time.
Verified Tool Facts & Data Sources
Uses real-time energy price benchmarks.
Includes bulb-lifespan amortisation.
Verified data from energy efficiency labels.
Privacy-first: Local calculation logic.
Machine-readable facts available at /facts.json

Detailed Methodology & Calculation Logic

Lighting Energy Logic

The calculator models energy usage by aggregating the power consumption of all bulbs in a scenario.

  • Energy Formula: Annual kWh = (Number of Bulbs × Average Wattage × Daily Hours × 365) / 1000.
  • Scenario Comparison: We compare your current 'Baseline' lighting (e.g., halogen or old LEDs) against 'Proposed' high-efficiency modern LEDs.
Financial & Payback Analysis

We analyze the total cost of ownership over 10 years, including the investment in new bulbs.

  • Annual Savings: Difference in energy cost between scenarios based on your local price per kWh.
  • Investment Return: The model tracks the cumulative cost to identify the point where energy savings have fully offset the purchase price of new bulbs.
Last updated: 2026-03-26