Capture calculator
Roof area × rainfall × runoff factor.
Tank sizing calculator
Dry-period demand with a reserve.
Demand estimator
Toilet, laundry, irrigation and other uses.
Overflow calculator
Incoming water, free storage and overflow.
Cost & payback
Simple water-value comparison.
Calculated in your browser
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Not engineering software: These tools provide preliminary estimates and cannot determine compliance, drinking-water safety, structural adequacy, flood performance or permit approval.