Irrigation Water Calculator
Calculate weekly irrigation water needs based on lawn or garden area, plant water requirements, and rainfall.
Weekly Irrigation Water
1,246 gallons
Weekly Irrigation Water vs Irrigated Area
Formule
## How to Calculate Irrigation Water Needs Lawns and gardens need about 1 inch of water per week, including rainfall. ### Formula **Weekly Gallons = Area * (Need - Rainfall) * 0.623 / Efficiency** ### Irrigation Efficiency - Drip irrigation: 85-95% - Sprinkler: 60-75% - Flood/furrow: 40-60% Overwatering is the most common irrigation mistake, wasting both water and money.
Exemple Résolu
3,000 sq ft lawn needing 1 inch/week with 0.5 inches rain at 75% sprinkler efficiency.
- 01Water deficit: 1.0 - 0.5 = 0.5 inches
- 02Weekly gallons: 3,000 * 0.5 * 0.623 / 0.75 = 1,246 gallons
- 03Monthly: 1,246 * 4.33 = 5,395 gallons
- 04Season (26 weeks): 1,246 * 26 = 32,396 gallons
Questions Fréquentes
How much water does a lawn need?
Most lawns need about 1 inch of water per week during the growing season. Cool-season grasses may need slightly more in heat. Warm-season grasses are generally more drought tolerant.
When is the best time to water?
Water early morning (4-8 AM) to minimize evaporation and fungal disease. Avoid midday watering (high evaporation) and evening watering (promotes fungus).
How does drip irrigation compare to sprinklers?
Drip irrigation delivers water directly to roots at 85-95% efficiency versus 60-75% for sprinklers. Drip uses 30-50% less water for the same plant health.