Use our free Fish Tank Volume Calculator to convert aquarium dimensions into liters and US gallons, and estimate a safe weekly water change. Quick, accurate, and mobile-friendly.
Aquarium Volume → Liters & US Gallons (with 20% Water Change)
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How the Fish Tank Volume Calculator Works
Knowing the exact volume of your aquarium is essential for maintaining water quality and keeping fish healthy. This calculator uses your tank’s internal dimensions to estimate liters and US gallons, then adjusts for décor, gravel, and air gaps that reduce real water capacity. Accurate volume helps when setting up aquariums, dosing water conditioners, or adding treatments safely.
Measuring and Adjusting Volume
To calculate capacity, measure length × width × height. A rectangular tank of 100×40×50 cm equals 200 liters before displacement. Most aquariums lose around 10–15% to gravel and décor. Our tool applies this correction automatically, giving you a practical number instead of a theoretical maximum.
Water Change Recommendations
Regular partial water changes are vital. Most aquarists follow the 10–20% weekly change rule, which removes nitrates, stabilizes pH, and restores trace minerals. For further guidance, see PetMD’s Water Change Guide. Larger tanks may need less frequent changes, while smaller or heavily stocked tanks benefit from closer monitoring.
Why Tank Volume Matters
- Water stability: Bigger tanks dilute toxins and maintain steady temperatures.
- Medication & dosing: Correct volume ensures safe, effective treatments without overdosing.
- Stocking & filtration: Proper calculations help plan fish load, filter capacity, and long-term health.
More Resources
For deeper reading, see trusted resources on aquarium fishkeeping or consult veterinary advice for advanced care. Explore more tools like the Dog Age Calculator, Cat Age Calculator, and Pet Calorie Calculator. For unique pet gifts, visit the WVPet Store.