Aquarium Calculator

For accurate measurements:

• Length: Measure the longest side from inside glass to inside glass
• Width: Measure front to back, inside dimensions
• Height: Measure from inside bottom to your intended water line (not tank rim)
• Bowfront: Measure width at the deepest point of the curve
• Hexagon: Measure one flat side from corner to corner

Remember: Actual water volume will be less than total tank volume due to substrate, decorations, and equipment.

Common aquarium sizes and dimensions (L x W x H in inches):

• 10 gallon: 20 x 10 x 12
• 20 gallon long: 30 x 12 x 12
• 29 gallon: 30 x 12 x 18
• 55 gallon: 48 x 13 x 21
• 75 gallon: 48 x 18 x 21
• 125 gallon: 72 x 18 x 21

Water weighs approximately 8.34 lbs per gallon. Add to this:

• Glass tank: Approximately 10-12 lbs per 10 gallons capacity
• Gravel substrate: About 1.5 lbs per pound of gravel, typically 1-2 lbs per gallon
• Decorations and equipment: Variable, typically 5-15 lbs

Example: A 55-gallon tank can weigh over 600 lbs when fully set up! Ensure your stand and floor can support the weight.

The "inch per gallon" rule is a rough guideline with significant limitations:

• Body shape matters: A 3-inch goldfish produces far more waste than a 3-inch neon tetra
• Swimming patterns: Active fish like danios need more horizontal space
• Territorial needs: Cichlids and bettas require space for territories
• Filtration capacity: Better filtration can support slightly higher stocking
• Surface area: Oxygen exchange happens at the surface - wide tanks support more fish than tall tanks

Use this rule as a starting point, then research specific species requirements.

Substrate depth recommendations:

• Fish-only tanks: 1-2 inches of gravel is sufficient
• Planted tanks: 2-3 inches minimum for root growth
• Deep substrate beds: May require special layering to prevent anaerobic pockets

Quick calculation: For 1 inch of gravel, you need approximately 1 lb of gravel per gallon of tank capacity. A 2-inch bed requires about 1.5-2 lbs per gallon.