Aquarium Tools & Calculators
Free, practical calculators for every fishkeeper — size your tank volume, check your stocking, pick the right heater, plan a water change, measure your substrate, and dose aquarium salt with confidence.
Aquarium Volume Calculator
Work out how much water your tank really holds from its dimensions — in US gallons, litres, and cubic units — plus a net volume that allows for substrate, décor, and headspace
Fish Stocking Calculator
Check whether your tank is understocked, well stocked, or overstocked using the inch-per-gallon rule — add each species and count to see your total stocking level at a glance
Aquarium Heater Calculator
Find the right heater wattage from your tank volume, room temperature, and target temperature — rounded up to the nearest standard heater size you can actually buy
Water Change Calculator
Work out how much water to remove for a partial change and how much dechlorinator to add to the fresh tap water going back in — for a safe, consistent maintenance routine
Aquarium Substrate Calculator
See how many pounds and kilograms of gravel or sand you need to cover your tank's base to the right depth — enter the footprint and depth and get the weight to buy
Aquarium Salt Calculator
Get the right dose of freshwater aquarium salt for your tank — general tonic, stress relief, or an ich treatment level — in tablespoons and grams based on your water volume