Aquarium calculators

Sourced math for the basic freshwater-aquarium setup decisions. From volume + weight (the foundations) through stocking-density analysis (the compatibility-aware ceiling).

• Aquarium volume calculator

  Tank dimensions in inches → US gallons + liters. Supports rectangular, bow-front, cylindrical, and hex tanks. Uses NIST-exact 231 cubic inches per gallon.

• Water weight calculator

  Water volume → weight in pounds and kilograms. For floor-load planning on tanks above 75 gallons.

• Heater wattage calculator

  Tank volume + room/target temperature delta → recommended wattage. Cross-checked against published manufacturer sizing tables (Aqueon, Fluval, Eheim).

• Substrate calculator

  Tank footprint + bed depth → pounds and gallons of sand, gravel, or aqua-soil. Includes 10% padding so you don't end up short.

• Filter flow rate calculator

  Tank volume + stocking density → recommended filter GPH range. Accounts for the rated-vs-actual flow gap so the box rating you shop for matches working flow.

• Stocking density calculator

  Propose a stocking, get an honest verdict (safe / caution / overstocked / incompatible). Checks parameter compatibility, predator-prey, schooling minimums, tank-size minimums, and adjusted bioload — not just inches-per-gallon.

• Water change calculator

  Net volume + percent → per-session gallons, hauling weight, weekly + monthly cadence, and a verdict on whether the schedule is conservative-safe or recovery-only.