All tools

Aquarium Volume Calculator

Tank gallons, liters, water weight, and stocking.

Total volume
56.1 gal
212.4 L

Practical numbers

Filled to 90% (with substrate, decor)50.5 gal
Water weight468 lb / 212 kg
"Inch of fish" rule (rough)50 in

Stand strength matters. A 55-gallon tank weighs about 460 lb when full. Most stock furniture isn't rated for that. The "1 inch of fish per gallon" rule is a rough cap for community tanks; bigger or aggressive species need more space than that. Substrate, rocks, and rim glass cut usable volume by 5–15%.

About

Enter tank length, width, and height. Get the volume in US gallons and liters, plus the realistic 'filled' volume after substrate and decor, water weight, and a rough fish-stocking estimate. Useful before buying a stand.

How to use

  1. Enter L × W × H.
  2. Pick units.
  3. Read volume and weight.

FAQ

Is the 'inch of fish per gallon' rule reliable?+

Only as a rough cap for community tanks. Bigger or aggressive species need more space than that suggests, and bioload from a single 8-inch fish is more than from eight 1-inch fish.

Why does the stand matter?+

A 55-gallon tank weighs about 460 lb when full. Most stock furniture isn't rated for that. Buy or build a stand made for an aquarium.