Capacity guide
Rainwater tank sizes
Compare common tank capacities, then use your roof, rainfall and household demand to calculate what will actually work.
Garden and supplementary
Small capacities for outdoor and limited use
These sizes suit garden watering, stormwater retention and carefully defined non-potable uses. None of them is normally enough to supply a household on its own.
- 500 LA compact tank for garden watering or a small rainwater buffer where space is tight. It is not normally enough for whole-house supply.Size details →
- 1,000 LA small urban tank for limited outdoor use or a carefully defined non-potable use.Size details →
- 2,000 LA compact urban capacity for garden use, stormwater management or a limited household connection.Size details →
- 3,000 LA useful supplementary urban tank where a smaller footprint matters more than long dry-period autonomy.Size details →
- 4,000 LA mid-sized supplementary tank for larger gardens or selected non-potable household uses.Size details →
- 5,000 LA substantial supplementary tank that can cover garden and selected household uses when roof catchment supports it.Size details →
Large storage
Where whole-house supply starts to be realistic
The step between urban storage and full-size rural tanks. These sizes cover high supplementary demand, low-use properties, or one unit in a linked system.
- 9,000 LA larger storage step for high supplementary demand or a low-use property with constrained tank space.Size details →
- 10,000 LA common large storage class for substantial supplementary use or as one unit in a linked system.Size details →
- 13,500 LA middle step between urban storage and full-size rural tanks, useful where site access or footprint limits apply.Size details →
- 15,000 LA large single-tank capacity for substantial demand, or one component of a multi-tank rural system.Size details →
- 20,000 LA large storage class for low-demand whole-property scenarios or as part of a linked system.Size details →
Rural and whole-property
Full-size tanks for household supply
The largest single tanks on this site. Commonly considered for whole-household supply, though whether one is enough still depends on your roof, rainfall and actual demand.