Use the right aquarium calculator before you dose, stock, feed, or move a tank.
This page is the tool index. Pick the calculator that matches the decision you need to make, enter the tank numbers on that tool page, then use the result with the safety notes below.
Choose the tool by the decision
Best first step for medication dosing, fertilizer dosing, water changes, stocking, and tank moves.
Water Change CalculatorPlan the water volume to replace and understand how a change affects nitrate or treatment stability.
Fish Stocking CalculatorEstimate stocking pressure before adding fish to a community or schooling tank.
Fish Feeding Schedule CalculatorConvert fish count and feeding frequency into a practical routine that avoids overfeeding.
Aquarium Load-Bearing CalculatorEstimate filled tank weight before placing an aquarium on furniture, racks, or upper floors.
Tank Size ConverterConvert inches, centimeters, gallons, and liters when comparing tanks, stands, and equipment specs.
Fast route
| If you are trying to… | Start here | Do not skip |
|---|---|---|
| Dose medication or fertilizer | Aquarium Volume Calculator | Subtract substrate, hardscape, and empty space from nominal tank size. |
| Lower nitrate safely | Water Change Calculator | Match temperature and conditioner before the change. |
| Add more fish | Fish Stocking Calculator | Check adult size, aggression, filtration, and schooling needs. |
| Feed a mixed tank | Fish Feeding Schedule Calculator | Watch body condition and leftover food, not only the schedule. |
| Place a heavy tank | Aquarium Load-Bearing Calculator | Include water, glass, substrate, rock, stand, and equipment. |
Safety boundary
Calculator output is a planning estimate, not a guarantee. When fish are sick, water tests are unstable, or a tank is structurally heavy, use the result as a starting point and verify with real measurements.