Rain Garden Runoff Offset Calculator

Estimate rain garden runoff offset using roof area and infiltration.

Roof Area?

sq ft

Rainfall (in)?

in

Capture Percent?

%

Garden Area?

sq ft

Infiltration Rate?

in/hr

Infiltration Hours?

hrs

Quick Facts

Capture

Percent

Capture lowers runoff

Capacity

Infiltration

Capacity sets limits

Rainfall

Event

Event size matters

Decision Metric

Offset

Percent