Aquarium calculators for fishkeepers
Tank volume for any shape, water changes, CO2 from pH and KH, dry fertilizer dosing, substrate and the real weight of a filled tank. US and metric units, with the formulas shown so you can trust the numbers.
Tank
Tank
Aquarium Volume Calculator
How many gallons or liters your tank holds: rectangle, bow front, cylinder, hexagon and corner tanks.
TankAquarium Substrate Calculator
How much sand, gravel or aquasoil you need for a given depth, including sloped scapes.
TankAquarium Weight Calculator
How much a filled tank weighs: glass, water and substrate, so you can plan the stand and floor.
Water
Water
Water Change Calculator
What a water change does to nitrate (or any dissolved substance), and how big a change you need to hit a target.
WaterAquarium CO2 Calculator (pH / KH)
Estimate dissolved CO2 in ppm from pH and KH, and the pH that corresponds to your target CO2.