This tool provides a general estimate and does not replace professional veterinary advice.
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What is the Coral Stocking Level Calculator?
The Coral Stocking Level Calculator calculates how many corals can safely be stocked in a given tank size. Undersized housing is one of the most common and most fixable welfare problems in pet keeping, it affects everything from stress levels to exercise to litter/waste management.
Expect roughly 10-50 years with a coral, which is worth factoring into any long-term plan. They are a filter feeder, so their nutritional needs shift with age, size and activity. Corals are colonial animals, not plants, and depend on stable salinity, alkalinity, calcium and strong lighting. They are the least forgiving part of a reef tank, where stability matters more than any single value. Keep an eye out for bleaching from heat or light stress, tissue recession from unstable alkalinity, brown jelly infection. These are the conditions corals are most commonly seen for.
Coral quick facts
| Measure | Coral |
|---|---|
| Typical lifespan | 10–50 years |
| Diet | Filter feeder |
| Mature at | About 3 years |
| Clutch size | 0–0 eggs |
How does the Coral Stocking Level Calculator work?
The recommendation is based on published care-guide minimums for corals, scaled to the animal's current or expected adult size. The math is only as good as what you feed it, so an accurate, recent input matters more than the formula itself.
Factors that matter
- Adult size: housing should be sized for the animal's full-grown dimensions, not its current size if still young
- Number of animals being housed together, since space needs don't simply divide evenly
- Activity level and natural behavior, such as climbing, digging or swimming space
- Whether the space is temporary (travel/carrier) or permanent (everyday housing)
How do you use the Coral Stocking Level Calculator?
- Enter the tank volume in whichever unit you use (US gal, L, UK gal)
- Enter the adult body length in whichever unit you use (in, ft, cm)
- Pick your filtration and planting (Standard filter, no live plants, Strong filter or heavily planted, Minimal filtration)
- Press Calculate, then read the result alongside the sources listed below
Use this alongside your own observation, not instead of it. You notice changes in your coral that no calculator can pick up.
For related questions, see the other housing tools or browse every coral tool.
Before you rely on this
Averages hide a lot of variation. The figure here reflects what is typical for corals, but your coral may sit well outside it for perfectly ordinary reasons. Use the result to spot changes over time in your own animal rather than to compare it against other people's pets.
Sources and references
The formulas, reference ranges and species data behind the Coral Stocking Level Calculator come from these veterinary references, professional bodies and published research.
- RSPCAAdvice and Welfarerspca.org.uk(opens in a new tab)
- Merck Veterinary ManualExotic and Laboratory Animalsmerckvetmanual.com(opens in a new tab)
- pdsa.org.ukPDSA Pet Health Hubpdsa.org.uk(opens in a new tab)
- University of Florida IFAS ExtensionAquacultureedis.ifas.ufl.edu(opens in a new tab)
- Merck Veterinary ManualRoutine Care and Breedingmerckvetmanual.com(opens in a new tab)
- Built on veterinary referencesFormulas and ranges come from veterinary manuals, university research and welfare bodies, listed above for you to check.
- Instant resultsNo page reload, no waiting and no account. Enter your details and the result appears straight away.
- Private by designCalculations run in your browser. Nothing you enter is stored on our servers or shared with anyone.
- Always freeEvery XpertsPet tool is free to use, with no premium tier and nothing to sign up for.