Aquarium Volume and Weight Calculator
Enter the dimensions and read the gross volume, the water that actually goes in, the total filled weight and the distributed floor load.
Net water310.2 L
Choose the dimension basis
Were your measurements taken outside or inside the glass? Choosing outer dimensions subtracts the glass thickness from the inner volume.
Enter length, width and height
Enter all three in centimetres. If you are using outer dimensions, also give the glass thickness in millimetres.
Define water level and substrate
Freeboard and substrate depth determine how much water actually goes in. Aquasoil, sand and gravel have different bulk densities.
Add the hardscape volume
Rocks and wood displace water. Enter their approximate volume in litres and the net water figure adjusts accordingly.
Read the floor load
The kg/m² figure in the results panel is the distributed load the aquarium places on the slab — the first number architects ask for.
How many litres is my aquarium?
With inner dimensions in centimetres, multiply length × width × height and divide by 1000 to get litres. That is the gross volume, though. The water that actually goes in is what remains after substrate depth, freeboard and hardscape are subtracted — typically 70-80 percent of the gross volume in a planted tank.
What is the difference between outer and inner dimensions?
Outer dimensions are measured outside the glass and include its thickness. To get the inner volume, twice the glass thickness is subtracted from length and width, and once from the height. On a 120 × 60 × 55 cm tank with 12 mm glass this difference can exceed 30 litres.
Will the weight be a problem for my floor?
What matters is not the total weight but the load distributed over the footprint (kg/m²). Residential slabs are typically designed for around 200 kg/m². A long, narrow tank spreads the same volume over a wider base and therefore produces a lower load. If your figure exceeds that band, have a structural engineer review it.
Does this tool recommend glass thickness?
No. Volume and weight follow from geometry and material density and are dependable. Glass thickness depends on aspect ratio, glass type (float, low-iron, tempered), bracing and base construction, and requires a structural calculation. If you are planning a custom-size aquarium, send us your dimensions.
Is saltwater calculated differently?
Yes. Seawater is roughly 2.5 percent denser than freshwater. Switching the water selector to saltwater recalculates weight and floor load accordingly.