Use a simple fish plan and tank modifiers to see whether the setup looks comfortable, close, or overloaded on paper.
Adjusted Stocking Level
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Enter the tank size, fish plan, and care assumptions to see adjusted stocking percentage and remaining headroom.
Tap an example to prefill the calculator with sample values.
Comfortable community tank
Schooling fish in a planted setup
A good example of the classic inch rule still working reasonably well once light modifiers are layered on top.
Result: A small schooling community often lands well inside the comfortable zone
Near-limit mixed stocking
A fuller tank with a centerpiece fish
Useful when a plan looks fine by classic inches but tightens once the larger fish gets a heavier bioload factor.
Result: A centerpiece fish can pull a community tank closer to the limit than the plain inch rule suggests
Overloaded paper plan
Big bioload with weak maintenance support
Good for catching an overstocked concept before fish are added and the tank becomes harder to correct.
Result: Once larger fish and weaker maintenance are included, the same tank can look heavily overstocked