20 Gallon Long Tank Volume Calculator

20 gallon long - popular for breeding and community tanks - Calculate exact water volume.

20 Gallon Long Tank Volume Calculator

Calculate the exact water volume for this aquarium size. This 20.0 gallon (76L) calculator helps you determine precise water capacity for safe medication dosing and equipment sizing.

Knowing your exact volume is crucial for accurate water treatments, filter sizing, and heater selection. We account for fill height and provide equipment recommendations based on your actual water volume.

How to Use This Calculator

  1. 1.Tank dimensions are pre-filled based on standard specifications for this size
  2. 2.Verify these match your actual aquarium (always measure from inside the glass)
  3. 3.Adjust the fill height if needed - most tanks aren't completely full
  4. 4.Switch between imperial and metric units to match your preference
  5. 5.Get instant results: exact volume, weight, and equipment recommendations

What's your tank shape?

Enter Your Dimensions

in
in
in

Recommended Equipment

Heater Needed:
~65 Watts
Filter Flow:
94–140 GPH
Based on 5–7.5× tank turnover per hour

Popular Tank Sizes & Shapes

Quick links to pre-filled calculators for popular tank sizes and shapes.

Results

Volume
18.7 US Gallons
(71 L)
Actual water volume may be lower due to substrate and rock displacement
Water Weight: 156 lbs (71 kg)
Estimated filled weight: ~165 lbs (75 kg)
(water + glass only)