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180 Gallon Tank: Dimensions, Volume & Weight

A standard 180 Gallon aquarium measures about 72 x 24 x 25 in (182.9 x 61 x 63.5 cm) and holds 681.4 L (180 US gal) at its full nominal rating. At a typical 90% fill with 15 L of substrate and decor, usable water volume is about 598.2 L (158 US gal); filled, the water alone weighs about 1499 lb (679.4 kg). Figures use the exact 1 US gal = 3.785411784 L conversion and published standard external dimensions, compiled 2026-09-25.

Nominal size
180 US gal
Standard footprint
72×24×25 in
Nominal volume
681.4 L
Usable volume (90% fill)
598.2 L / 158 gal
Full tank water weight
1499 lb / 679.4 kg
Usable water volume by fill level, after 15 L of substrate and decor
Fill levelUsable volume (L)Usable volume (US gal)
80%530.1140
90%598.2158
100%666.4176

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Dimensions, weight, and fill assumptions

These are typical external footprint dimensions published across major US tank manufacturers' standard-size charts, not a measurement of one specific tank on a shelf; rimless, low-iron, and non-US models can differ by an inch or more per side. The nominal 180 US gal rating is the manufacturer's full-tank figure, so it slightly overstates the water you will actually keep: after subtracting a typical 15 L (about 4 US gal) of substrate, decor, and hardscape, and filling to a realistic 90% of the rim height to leave room for equipment and evaporation, usable volume drops to 598.2 L. Water weight uses fresh water at about 25 degrees C (0.997 kg/L, 8.328 lb/US gal); a filled tank also carries the glass, stand, substrate, and hardscape, so total load on a floor or stand is higher than the water weight alone. The prefilled link below opens TankStockPlan with this size's typical external dimensions, a 90% fill, and 15 L of displacement already entered; replace the length, width, and height with your own internal (inside-the-glass) measurements for an exact usable-volume figure, since that is what actually determines how much water and livestock the tank can support. Prioritize animal welfare. A specialist-reviewed husbandry plan and a properly cycled, stable aquarium are required; this calculator is not approval to add fish.

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Reference sources

Published standard rectangular aquarium dimensions (major US manufacturer size charts); 1 US gal = 3.785411784 L is SI-exact.