Aquarium Volume Calculator

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Aquarium Volume Calculator: Complete Guide to Tank Size, Weight & Equipment

Setting up a new aquarium? Our aquarium volume calculator gives you exact volume in gallons and liters, total weight, filter pump size, heater wattage, and substrate needs — all in one click.

How to Use the Calculator

  1. Choose your tank shape (rectangular, bowfront, cylinder, etc.)
  2. Enter length, width, height in inches
  3. Add optional glass thickness and substrate depth
  4. Get instant results for volume, weight, and equipment

Volume Calculation Formulas

  • Rectangular: L × W × H ÷ 231 = gallons
  • Bowfront: Uses adjusted width formula
  • Cylinder: π × r² × h ÷ 231
  • Hexagonal: 2.598 × s² × h ÷ 231

Example: 24×12×12 Rectangular Tank

Volume: 20 gallons
Water Weight: 167 lbs
Glass Weight: ~15 lbs
Total Weight: ~182 lbs
Filter: 100 GPH
Heater: 100 W
Substrate (2" depth): 24 liters

Standard Aquarium Sizes Chart

SizeDimensionsVolumeWeight (Full)
10 Gallon20×10×1210 gal~111 lbs
20 Gallon24×12×1620 gal~225 lbs
55 Gallon48×13×2155 gal~625 lbs
75 Gallon48×18×2175 gal~850 lbs

Filter Pump Sizing (Turnover Rate)

  • Freshwater: 5× volume per hour
  • Planted: 6–8×
  • Reef: 10–20×

Heater Wattage Guide

  • 5 watts per gallon (up to 80°F)
  • 3 watts per gallon (tropical 75–80°F)
  • Always use two smaller heaters for redundancy

Substrate Calculator

2" depth is ideal for most plants. Use our calculator to avoid buying too much gravel or sand.

Weight Considerations

  • Water: 8.34 lbs per gallon
  • Glass: ~12 lbs per square foot (1/4" thick)
  • Stand must support full weight + 20% safety margin

Pro Tips for Aquarists

  • Measure inside dimensions for accuracy
  • Account for displacement from decorations
  • Place tank on level, reinforced floor
  • Use our pet food calculator for fish feeding

Common Mistakes to Avoid

  • Overstocking based on volume alone
  • Using undersized filter
  • Placing tank near windows (algae growth)

FAQs

How many fish per gallon? 1 inch of fish per gallon (slim-bodied).

Can I use cm instead of inches? Convert: 1 inch = 2.54 cm.

Does substrate reduce water volume? Yes — 1" depth reduces ~0.5 gal per sq ft.

Conclusion

Proper planning prevents disasters. Use our free aquarium volume calculator before buying your next tank. Save money, avoid leaks, and keep fish healthy.

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