🔥 Heater Wattage Calculator
Calculate the perfect heater size for your aquarium or terrarium based on volume and temperature requirements.
thermostat Tank & Environment
Please enter a valid tank volume
°C
°C
Room: 20°C
Target: 25°C
ac_unit
Temperate
wb_sunny
Tropical
whatshot Recommended Heater
0 W
for your aquarium
Formula:
Base: 3-5 W/gallon (0.8-1.3 W/L)
Adjusted for ΔT, tank type & climate
Base: 3-5 W/gallon (0.8-1.3 W/L)
Adjusted for ΔT, tank type & climate
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🔌 Heater Types
Submersible Heater
Most common, fully submersible, various sizes
Hang-on-Back (HOB)
Easy to install, good for small to medium tanks
In-Line Heater
External filter integration, great for large tanks
Undergravel/Cable Heater
Placed under substrate, provides even heating
📏 Sizing Guidelines
- Small tanks (under 75L): 25W – 100W heater recommended
- Medium tanks (75L – 200L): 100W – 200W heater range
- Large tanks (200L – 400L): 200W – 300W heater needed
- Extra large (400L+): 300W+ or use multiple heaters
- Saltwater tanks need 10-15% more wattage than freshwater
- Cold rooms require 20-30% additional heating capacity
- Use 2 heaters for tanks over 300L for redundancy
⚠️ Safety: Always use a heater guard and check temperature daily. Never operate heater outside water.
