Inputs
ft
ft
ft
ft²
If known, enter the total sprinklered area.
Nozzle Library
psi
Applies flow/head and suggests spacing using radius × 2.
ft
Head-to-head spacing along length.
ft
Head-to-head spacing along width.
gpm
gpm
Check if zone flow exceeds this capacity.
in/hr
in
Water to apply per irrigation.
%
Distribution efficiency (DU/CU proxy).
Hydraulics & Valve Sizing
Schedule 40 inner diameters.
ft
ft/s
psi
psi
ft
psi
psi
Pipe Velocity
—
ft/s (at zone flow)
Pipe Friction Loss
—
psi over length
Valve ΔP (selected)
—
psi
Pressure budget will appear after calculation.
Example Data
| Zone | Shape | Length | Width | Radius | Sx | Sy | Pattern | Flow/Head | Target Depth | Efficiency | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Lawn Front | Rectangle | 30 | 20 | - | 15 | 15 | Square | 1.8 | 0.5 | 75% | |
| Courtyard | Circle | - | - | 12 | 12 | 12 | Triangular | 1.2 | 0.4 | 70% | |
| Planting Beds | Known Area | - | - | - | 10 | 10 | Square | 0.8 | 0.6 | 80% |
Click “Load” to populate input fields with the row’s values.
Results
Zone Area
—
ft²
Heads Needed
—
rows × cols
Total Flow
—
gpm
Precip. Rate
—
in/hr
Runtime per Irrigation
—
minutes at target depth
Weekly Water
—
in/week
Layout Preview
Overlay multiple scenarios; each gets its own markers and color.
Zone Area & Coverage Summary
| Metric | Value | Units |
|---|---|---|
| Zone Area | — | — |
| Perimeter | — | — |
| Heads per normalized area | — | — |
| Theoretical cell area | — | — |
| Actual area per head | — | — |
| Difference | — | % |
Normalized area is 1000 ft² or 100 m², depending on units.
Runtime & Water Budget
| Metric | Value | Units |
|---|---|---|
| Target depth per irrigation | — | — |
| Runtime per irrigation | — | minutes |
| Irrigations per week | — | events/week |
| Weekly water depth | — | — |
| Volume per irrigation | — | — |
| Weekly volume | — | — |
| Monthly volume (≈4 weeks) | — | — |
Volumes use total zone flow and computed runtime.
Formulas Used
- Rectangle area = length × width.
- Circle area = π × radius².
- Grid heads: cols = ⌊length / Sx⌋ + 1; rows = ⌊width / Sy⌋ + 1 (rectangle).
- Triangular stagger: odd rows offset by Sx/2 (density ≈ 0.866 × Sx × Sy per head).
- Total flow = heads × flow_per_head.
- Precipitation (Imperial): PR (in/hr) = 96.3 × Total_GPM ÷ Area_ft².
- Precipitation (Metric): PR (mm/hr) = 60 × Total_L/min ÷ Area_m².
- Runtime (minutes) = Target_Depth ÷ (PR × Efficiency) × 60.
- Weekly water = PR × runtime_hours × days/week.
- Hazen–Williams headloss (ft): 4.52 × L × Q1.85 ÷ (C1.85 × d4.87).
- Valve ΔP (Cv) (psi): (Q_gpm ÷ Cv)2, water SG≈1.
- Velocity v (ft/s) = Q_cfs ÷ Area_ft²; Q_cfs = gpm ÷ 448.831.
Values are planning estimates. Verify with manufacturer data and local codes.
How to Use
- Select units, zone shape, and grid pattern.
- Optionally choose a nozzle; apply to set flow and spacing.
- Enter dimensions, spacing, target depth, and efficiency.
- Click Calculate to compute area, heads, flow, and runtime.
- Use hydraulics to check friction, velocity, and valve pressure drop.
- Save scenarios; hover chips to compare overlays on the chart.
- Export single reports or combined multi-scenario CSV/PDF.
FAQs
A common guideline is head-to-head coverage: spacing roughly equals the nozzle radius. Adjust using precipitation, uniformity goals, wind, and site shape.
Triangular staggering typically improves uniformity and slightly increases head density (≈13%). Square grids are simpler to stake out and estimate.
We divide the total zone flow by the zone area, then convert units: in/hr = 96.3 × GPM/ft²; mm/hr = 60 × L/min/m².
For well-designed turf zones, 70–85% is common. Micro-irrigation can be higher; windy or irregular sites may be lower.
We limit velocity, estimate pipe friction by Hazen–Williams, and compute valve ΔP using Cv. The smallest size meeting limits is suggested.
Library values are representative at specific pressures. Always confirm with the manufacturer chart for your exact model and angle.
Yes. Save scenarios to overlay layouts and export combined CSV/PDF. Hover to highlight; enable pin to lock comparisons visibly.