Irrigation Water Usage Calculator
How many gallons does a watering actually use? This multiplies your irrigated area by the water depth you apply, then projects weekly and seasonal totals for budgeting and cost.
Formula: gallons per watering = area (sq ft) × depth (in) × 0.623. Weekly = per-watering × days; monthly ≈ weekly × 4.33; seasonal = weekly × weeks; cost = seasonal gallons ÷ 1,000 × $/1,000 gal. Use: budget irrigation before the season, compare watering schedules, and size rain-barrel or well capacity.
FAQ
How many gallons to water 1,000 sq ft?
1 inch over 1,000 sq ft is about 623 gallons. A half-inch watering is about 311 gallons; a 1-inch weekly watering across 5,000 sq ft is about 3,115 gallons.
How do I reduce irrigation water use?
Subtract rainfall from your target depth, water deeply and less often to encourage deep roots, fix leaks and misaligned heads, use drip for beds, and mulch to cut evaporation.
What is the water cost formula?
Multiply your seasonal gallons by your water rate (typically $ per 1,000 or 100 cu ft). Example: 100,000 gal at $5/1,000 gal is $500 for the season.
Figures are editable example defaults for planning, not guarantees. Water needs vary by crop, soil, weather, season, and local climate — check ET data (NOAA, your state CIMIS/AgriMet network) and verify with your local extension service or agronomist.