Plan irrigation coverage with simple, accurate inputs. Adjust arc, spacing, and wind loss for realism. Export results, refine zones, and avoid dry patches today.
| Scenario | Unit | Radius | Arc | Heads | Overlap | Loss | DU | Notes |
|---|---|---|---|---|---|---|---|---|
| Open lawn zone | m | 6.0 | 360° | 4 | 90% | 8% | 85% | Good overlap, minimal wind. |
| Edge strip | m | 5.0 | 180° | 6 | 85% | 10% | 80% | Half-arc along a fence line. |
| Corner beds | m | 4.0 | 90° | 8 | 80% | 12% | 78% | Quarter-arc near planting corners. |
| Warm, breezy day | ft | 18.0 | 360° | 5 | 85% | 20% | 75% | Increase run time or reduce loss. |
| Compact patio border | ft | 12.0 | 120° | 7 | 88% | 12% | 82% | Custom arc helps reduce overspray. |
Use the sector equation to compare full, half, and quarter spray patterns. With radius r and arc θ, theoretical area equals (θ/360)×π×r². This quantifies how border trimming reduces wetted ground, and it supports mixing arcs in one zone. Record measured radius at operating pressure for accuracy. For irregular shapes, calculate each arc separately and sum the results.
Real watering rarely matches perfect geometry. The calculator applies three practical multipliers: overlap efficiency, wind/evaporation loss, and distribution uniformity. Multiply them to form one effectiveness factor. Effective area is theoretical area × factor. For many residential systems, overlap 80–95% and DU 70–85% are reasonable starting points. If you have catch‑can test data, enter that DU to match measured uniformity.
Head spacing influences overlap and uniformity. A fast check is spacing ÷ radius. Values near 1.0 often indicate head‑to‑head layout; ratios above 1.1 can weaken midpoints, especially with low DU. Ratios below 0.8 may increase runoff and overspray. Adjust arcs and nozzle types before increasing run time. When spacing changes, keep nozzle families consistent to maintain similar precipitation rates.
Wind loss is a simple percentage that reduces effective area. Increase it on exposed lawns, slopes, or hot afternoons where droplets drift and evaporate. For sheltered courtyards, use a lower loss. Combine this with DU to reflect nozzle wear, pressure variation, and maintenance. Recheck settings seasonally and after repairs. On windy sites, low‑angle nozzles and early watering windows can reduce loss.
Total effective area equals effective area per sprinkler × number of sprinklers. Compare this with your zone’s measured area to judge whether you need more heads, different arcs, or tighter spacing. Use the target area option to estimate minimum heads required. Export CSV for records and PDF for proposals, inspections, and crew briefings. Label exports with zone details.
Enter the measured throw distance at your actual operating pressure, not the catalog maximum. Measure from the head to the outer wet edge. Recheck after changing nozzles, filters, or regulators.
Use 360° for full coverage, 180° for edges, and 90° for corners. For adjustable heads, enter the set arc. Mixing arcs is fine; calculate each type separately if you need a detailed plan.
It approximates how well adjacent heads overlap to avoid dry gaps. Head‑to‑head layouts often justify 85–95%. Wider spacing or mismatched arcs should use lower values until field tests confirm performance.
Use 5–12% for calm, cool conditions and 15–25% for warm, breezy exposure. Increase the value for slopes or open sites. Reduce it for sheltered zones, then validate with visual coverage checks.
Distribution uniformity reflects how evenly water is applied across the zone. Higher DU means fewer dry spots at the same runtime. If you have catch‑can testing, enter that measured DU; otherwise start around 75–85% and refine.
No. It is a planning estimator for coverage area. It does not model precipitation rate, pressure losses, or hydraulic limits. Use it to compare options, then confirm final layouts with onsite measurements and manufacturer guidance.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.