Heater Wattage Calculator

Work out what size aquarium heater you need based on your tank volume, room temperature and target water temperature.

Heater Size Calculator

Enter your tank size and temperatures to estimate the ideal heater wattage and setup.

Tropical community tanks are usually kept around 24–26°C. We’ll start with 25°C as a target.

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Not sure of your tank volume? Use our tank volume & water weight calculator .

°C

Estimate the coldest temperature your room usually reaches where the tank is kept.

°C

This can change based on species (e.g. goldfish a bit cooler, bettas a bit warmer).