Rain Calculator
How much water is falling off your roof?
Every square foot of roof sheds about 0.62 gallons per inch of rain. Our seamless systems capture roughly 95% of it.
Rain Catchment Calculator
What your roof can harvest
2,500 sq ft
1,0006,000
- Harvestable water
- ~1,480 gal
- per 1-inch rain event
- Municipal rebate
- Up to $740
- Austin Water $0.50/gal, no pump
- Sales tax saved
- 8.25%
- Tax Code § 151.355
How the numbers work
- Harvestable water
- Roof sq ft × 0.623 gallons × 95% collection efficiency × inches of rain. Pick a 1-inch rain, a 2-inch deluge, or Austin's 32-inch average year.
- Municipal rebate
- Modelled on Austin Water: $0.50 per gallon for a system without a pump, or $1.00 per gallon if you add one. Sized on a 1-inch rain and capped at $5,000. For LCRA WaterSmart, New Braunfels Utilities and other providers, our Rebate Concierge checks the current program for you.
- Sales tax saved
- 8.25% combined state and local sales tax, exempt under Texas Tax Code § 151.355 and claimed with Form 01-339.
Estimates only. Final rebate amounts depend on utility approval, pre-inspection and installed storage capacity.