A worked example
One heater on its own
- Start with
- 100 W · 8 h/day · 30 days · $0.20/kWh
- Check the result
- 24 kWh · estimated $4.80
Remove other devices or set their quantities to zero. Currency labels follow the page language.
Everyday tool
Aquarium Electricity Cost Calculator
Which device contributes most to running costs? Compare wattage and active hours for heaters, filters, and lights.
Entered rate only; tiered and fixed charges are separate
Equipment electricity estimateAdd each device's wattage and actual daily runtime.
Editable rateEquipment listFor a thermostat heater, enter estimated active hours—not 24 hours.
DeviceWh/dayQty
Estimated monthly cost
30-day estimate$6.8442.7 kWh
Connected wattage146 W
Yearly estimate$82.02
Yearly usage512.6 kWh
Devices4 devices
Cost by device
Heater (estimated runtime)$3.84
Filter$1.38
Light$1.15
Air pump$0.46
This is a simple estimate using the rate you entered. Your utility bill may include tiers, taxes, fixed charges, seasonal rates, and other household electricity use. Heater runtime varies with room temperature, tank size, lid, and set temperature.
Equipment electricity
Separate plugged-in time from active runtime
Enter each device
Add watts, active hours per day, and quantity for each heater, filter, or light. Add missing devices and remove unused ones.
Estimate heater runtime
Use hours spent heating rather than hours plugged in. Change runtime to compare different room-temperature conditions.
Check period and rate
Set days and price per kWh, then read device costs. The yearly display multiplies the selected period’s usage and cost by 12.