Advanced options included
Calculate watering volume and runtime
Submit the form to show results above the inputs.
Run one calculation to enable downloads.
Calculator
Example data table
| Scenario | Area | Mode | Key inputs | Typical output |
|---|---|---|---|---|
| Raised bed vegetables | 10 m² | Depth-based | Depth 12 mm, drip 90%, rain 0 | ~133 L per event |
| Small lawn patch | 300 ft² | Depth-based | Depth 0.5 in, sprinkler 70%, rain 0 | ~230 gal per event |
| Container garden | 4 m² | Soil-based | Root 15 cm, potting AWC 110, MAD 40% | ~29 L per event |
Outputs are approximate and depend on actual infiltration and uniformity.
Formula used
1) Convert depth to volume
Because 1 mm over 1 m² equals 1 liter:
Volume (L) = Area (m²) × Gross depth (mm)
2) Account for effective rainfall
Effective rain (mm) = Rain (mm) × Effective %
Net depth (mm) = Target depth (mm) − Effective rain (mm)
3) Account for irrigation efficiency
Gross depth (mm) = Net depth (mm) ÷ Efficiency
Efficiency captures drift, evaporation, and non-uniformity.
4) Soil-based refill (optional mode)
Uses soil storage and allowed depletion:
Refill depth (mm) = Root depth (m) × AWC (mm/m) × MAD
How to use this calculator
- Choose a mode: use depth-based for a known target depth, or soil-based when you know root depth and soil storage.
- Enter the planted area: measure only the area that receives water.
- Select method and efficiency: keep the suggested value, or edit it to match your setup.
- Add rainfall if relevant: include rain since last watering, and adjust effective percent for runoff.
- Optional runtime: add your total system flow rate to estimate minutes per event.
- Export and track: download CSV or PDF, then refine settings using plant response and soil moisture checks.
Built for planning; always confirm with field observations.