01 · Volume

Aquarium volume calculator - litres, gallons, glass thickness.

Type in interior length, width, and height. Subtract the substrate. Get net liters, US gallons, surface area, footprint, and a sensible single-pane glass thickness – instantly, in your browser.

Dimensions
Unsafe Limit Safe
Net volume
57.6litres
Gross64.8 L
Min glass4 mm
Deflection0.42 mm
Surface18 dm²
Footprint60×30
Substrate7.2 L
Glass weight
12.3 kg
Total (glass + water)
70 kg
Cut list (cm)
  • Front60×36
  • Rear60×36
  • Left29.2×36
  • Right29.2×36
  • Bottom59.2×29.2
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How aquarium volume is calculated

Aquarium volume is just length × width × height. The trick is that aquarists almost always quote a tank by its gross volume – the headline number on the box – when what actually matters for stocking, dosing, and water changes is the net volume: gross minus everything that isn't water.

Substrate displaces real water – a 5 cm sand bed in a 60 × 30 cm tank steals 9 litres. Rocks and wood take more. Equipment (heater, internal filter, CO₂ diffuser) eats a litre or two. Real-world net volume usually runs 80–90% of the headline figure.

Glass thickness - a sensible rule

Hydrostatic pressure rises with depth, not surface area. The classic rule of thumb is height in cm ÷ 18 rounded up, with a safety factor of about 3.8. A 36 cm tall tank wants 4 mm glass; a 60 cm tall tank wants 6 mm. Tempered (toughened) glass is stiffer, but if it ever fails, it fails catastrophically – annealed is the safer choice for home aquariums.

How do I calculate aquarium volume in litres?
Multiply interior length × width × height in cm, then divide by 1000. A 60 × 30 × 36 cm tank holds 64.8 litres gross. Subtract substrate displacement for net volume.
Should I use interior or exterior dimensions?
Always interior. Exterior measurements include the glass, which holds no water.
How thick does my aquarium glass need to be?
A common rule of thumb is height (cm) ÷ 18 = thickness in mm, with a safety factor of ~3.8.
Why is my actual volume lower than the calculator says?
Substrate, rocks, wood and equipment all reduce real volume. Most tanks hold 80-90% of gross once aquascaped.
How do I convert litres to US gallons?
Multiply litres by 0.264172.
Try another

Three more little maths machines.

Water change Salts for RO/DI top-off
Fertilization Dry-salt dosing & EC
CO₂ concentration From pH, KH & temp

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