Tips
How to use Aquarium Volume Calculator
- Use internal tank dimensions for the most accurate estimate.
- Actual volume may vary depending on the shape and porosity of substrate, rocks, wood, and equipment.
Everyday tool
Aquarium Volume Calculator
Calculate gross capacity and estimated actual water volume while accounting for water level, substrate, and decorations.
Tank dimensionsEnter inside dimensions for a closer estimate.
Dimensions & water levelUse inside measurements when possible
Volume deductionsApproximate substrate and hardscape
Estimate method
The calculator estimates solid displacement by substrate type, then deducts the decoration percentage. Enter rocks, wood, internal filters, and similar items as one combined percentage.
Estimated result
Actual water volume49.3 L13 US gal
Gross capacity66.1 L
At actual water level56.6 L
Substrate deduction− 4.7 L
Decor deduction− 2.6 L
Water weight≈ 49.3 kg
Estimated setup weight≈ 68.4 kg
Estimated setup weight includes water, estimated substrate, and your entered empty-tank/equipment weight. Confirm the stand and floor load separately for large tanks.
Equipment guidePractical starting points based on actual water volume
Recommended heater25 W
Round up to a common heater size; use two smaller heaters for large tanks.
Recommended filter flow52.1 GPH – 78.2 GPH
Nominal flow before media, hose, and head-height losses.
20% water change9.9 L
2.6 US gal
30% / 50% water change14.8 L / 24.7 L
Use a schedule suitable for your livestock and test results.
Equipment recommendations are general estimates, not manufacturer specifications. Room temperature, lid, flow restriction, stocking level, and species needs can require different equipment.
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All conversion and calculation happens in your current browser. Baro Tool does not save your input or results on its server.