Aquarium Volume Calculator

Calculate your tank volume in gallons and liters. Works for rectangle, bowfront, cylinder, hexagon, and corner tanks.

Length (in)

Width (in)

Height (in)

Gross Volume

39.9 gal

151.0 liters

Usable Volume (~90%)

35.9 gal

After substrate & décor

Shape

Rectangle

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Free tools for tank volume, stocking, substrate, filtration, and more.

Calculate tank volume in gallons and liters for any shape.

Check if your tank is properly stocked and find compatible fish.

Calculate how much gravel, sand, or soil you need.

Find the right heater wattage for your tank.

Calculate required filter GPH and recommended filter type.

Calculate minimum safe glass thickness for DIY tanks.

Calculate salt mix amounts for marine and brackish tanks.

Find the right light intensity for your tank type.

Calculate dissolved CO2 from pH and KH readings.

Calculate exact doses for fertilizers and medications.

Calculate total tank weight including water, glass, and substrate.

Estimate complete setup cost with equipment recommendations.

Disclaimer: Calculators provide estimates. Always research species compatibility and cycle your tank before adding fish.