Calculate your cost
Start with the example below, then replace the wattage, daily runtime, and rate with the numbers for your aquarium light.
This setup uses about 5 kWh in a 30-day month.
Please enter valid values within the ranges shown.
| Schedule | Hours/day | Cost/month |
|---|---|---|
| Half runtime | 0.5 | $0.42 |
| Page example | 1 | $0.85 |
| Longer runtime | 1.5 | $1.27 |
Same 150-watt input and 18.83¢/kWh rate; only runtime changes.
Formula for the page example
0.15 kW × 1 hr × $0.1883 = $0.03 per day
Convert watts to kilowatts, multiply by the active hours used each day, then multiply by the electricity price in dollars per kWh. Multiply the daily result by 30 for the monthly estimate shown above.
How to read this estimate
This is a standard household appliance found in many modern homes, providing everyday convenience and utility.
Use this as a baseline until you can check the label or measure the aquarium light directly. Model, settings, condition, climate, and household routine can all change the result.
What changes the cost?
- 01
Time used
- 02
Device wattage
- 03
Local electricity rate
Ways to spend less
- Unplug when not in use
- Use efficiently
- Regular maintenance