Rain Barrel Calculator

How It Works

Rainwater harvesting is one of the simplest and most effective ways to reduce your water bill and provide your garden with chemical-free water. A single inch of rain falling on a 1,000 sq ft roof produces 623 gallons of water -- enough to supply a 100 sq ft garden for over a week. Standard rain barrels hold 55 gallons, but even one barrel makes a meaningful difference. Connect the barrel to a downspout with a diverter kit ($20-30) so it fills automatically during rain. Use a soaker hose or watering can to distribute the water. In most climates, a roof can collect far more water than a small garden needs, so the real question is storage capacity. Check local regulations -- a few states restrict rainwater collection, but most encourage it.