Irrigation / Watering Schedule Calculator
Calculate your lawn watering schedule based on area, water needs, and sprinkler output.
Get optimal run times in minutes per zone.
Watering Schedule
Irrigation scheduling calculates how long to run sprinklers to deliver the right amount of water.
Run Time (minutes) = (Water Needed per Week / Sprinkler Rate) × 60
Sessions per Week = Total Weekly Need / Water per Session
Unit conversions:
Imperial: Area in sq ft, water in inches/week, sprinkler rate in inches/hourMetric: Area in m², water in mm/week, sprinkler rate in mm/hour1 inch = 25.4 mm
Typical water needs:
| Grass Type | Inches/Week | mm/Week |
|---|---|---|
| Cool-season (fescue, bluegrass) | 1.0–1.5 | 25–38 |
| Warm-season (bermuda, zoysia) | 0.75–1.25 | 19–32 |
| Buffalo grass | 0.5–0.75 | 13–19 |
| Flower beds | 1.0–2.0 | 25–50 |
| Vegetable garden | 1.0–1.5 | 25–38 |
Typical sprinkler output rates:
| Sprinkler Type | Inches/Hour | mm/Hour |
|---|---|---|
| Rotary heads | 0.4–0.6 | 10–15 |
| Fixed spray heads | 1.0–2.0 | 25–50 |
| Drip irrigation | 0.5–1.0 | 13–25 |
| Oscillating | 0.5–1.0 | 13–25 |
Tips:
- Water early morning (4–8 AM) to reduce evaporation
- Split into 2–3 sessions per week rather than daily light watering
- Deep, infrequent watering encourages deeper root growth
- Reduce by 30% in spring/fall, skip in rainy periods