Lighting Energy Cost Calculator

Know what your garden lights cost monthly now. Model LED, solar backups, and timers fast. Save energy by tuning hours, brightness, and quantity smartly.

Calculator Inputs
Plan grow lights, landscape lights, and greenhouse fixtures.
Use the real draw, not the “equivalent” rating.
Use 100 for full power, 60 for typical dimming.
For seasonal decor or weekend pathways, reduce days.
For smart drivers, sensors, hubs, or controllers.
Seasonal schedule (optional)
Useful when winter nights are longer than summer nights.
Summer + Winter should total 12.
When enabled, the calculator uses a weighted average hours/day from your summer and winter settings.
Electricity rate options
Use a flat price per kWh or tiered tariffs.
Example: 0.25 means currency 0.25 per kWh.
Optional: estimate emissions for the selected period.
If you choose tiered rates, Tier 1 and Tier 2 are capped, while Tier 3 covers anything above those limits.
Optional upkeep cost
Include bulbs, drivers, cleaning, or replacements.
Allocated to your selected period automatically.
This is useful for garden lighting that needs periodic cleaning, waterproof seals, or driver replacement.
Example Data Table
Sample scenarios for common garden lighting setups.
Illustrative only
Use case W/fixture Qty Hours/day Days/week Rate/kWh
Pathway LEDs with timer 7 10 5 7 0.24
Grow lights for seedlings 40 6 8 7 0.25
Security floodlight with sensor 30 2 2 7 0.28
Greenhouse strip lighting (dimming 60%) 18 8 10 6 0.22
Formula Used
This calculator estimates energy and cost with dimming, standby draw, schedules, and tariff options.
Run Watts = Wattage × Quantity × (Dimming ÷ 100)
Run kWh/day = (Run Watts × Active Hours/day) ÷ 1000
Standby kWh/day = (Standby Watts/fixture × Quantity × Standby Hours/day) ÷ 1000
Effective kWh/day = (Run kWh/day × (Days/week ÷ 7)) + Standby kWh/day

Period kWh = Effective kWh/day × Period Days
Flat Cost = Period kWh × Rate
Tiered Cost = Σ (Tier kWh × Tier Rate) across tiers
Seasonal mode replaces “Active Hours/day” with a weighted average from summer and winter settings. Monthly uses an average month length (30.4375 days) for realistic budgeting.
How to Use This Calculator
  1. Enter fixture wattage, quantity, and average brightness percentage.
  2. Set the daily hours and how many days per week you use them.
  3. If your schedule changes by season, enable seasonal hours.
  4. Choose flat pricing or tiered tariffs, then enter your values.
  5. Press Calculate to view costs above the form under the header.
  6. Download CSV or PDF for sharing and record keeping.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.