Free Sprinkler System Design Tool
Draw your yard, drop the heads with head-to-head spacing, split it into zones your water supply can actually run — and walk away with a parts list. Everything in feet, GPM and PSI. Nothing to install.
Draw Mode
Sketch the yard, type the side lengths in feet, and drop heads exactly where you want them. Full control over every detail.
GPS Mode
Trace the lot from satellite imagery, or walk the property line with your phone and let the outline draw itself. No tape measure needed.
Parts List
Exact heads, pipe runs in feet, valves and fittings, counted off your own drawing. Print it or share it straight from the app.
Coverage Simulation
See the spray arcs overlap in real time and catch dry corners or pooling before a single trench is dug.
How it works
Draw or import your yard
Sketch it with the drawing tools, trace it from satellite view, or walk the boundary and let GPS import the shape.
Place heads and split the zones
Drag heads into position or let the algorithm space them head-to-head, set the throw radius in feet, and group them into zones your flow can run.
Get your parts list
Pipe runs, heads, valves and fittings are counted off the drawing automatically. Print it or share it from the app.
Why plan before you dig?
A well-designed system cuts water use by 30–50% against hand-watering or heads laid out by eye. Every decision that matters — spacing, zone splits, pipe size — has to be made before the first trench, because after that you are digging up your own lawn to fix it. This tool lets you get it wrong on screen instead: move heads, resize zones, watch the coverage arcs overlap, and print the parts list before spending a dollar.
The head-to-head principle is the one rule that decides whether a residential system works: every sprinkler's spray has to reach the next head. Space them farther apart than the throw radius and you get crescent-shaped dry patches no matter how long you run the zone — the single most common failure in a DIY install, and the reason a 15 ft head belongs on a 15 ft grid rather than the 20 ft one that "looked about right" from the patio.
Sprinkler spacing chart (head-to-head, in feet)
Spacing equals throw radius on a square grid. A triangular grid packs the same heads about 15% farther apart for equal coverage, which is why it uses fewer heads on open lawn — at the cost of a layout that is harder to lay out by hand and easy to draw here.
| Head / nozzle | Throw radius | Square grid | Triangular grid | Typical use |
|---|---|---|---|---|
| 8 ft spray | 8 ft | 8 ft | 9 ft | Narrow strips, parkways |
| 10 ft spray | 10 ft | 10 ft | 11.5 ft | Small front lawns, beds |
| 12 ft spray | 12 ft | 12 ft | 13.5 ft | Most residential turf |
| 15 ft spray | 15 ft | 15 ft | 17 ft | Open lawn areas |
| Short-range rotor | 25 ft | 25 ft | 28 ft | Mid-size back yards |
| Standard rotor | 35 ft | 35 ft | 40 ft | Large open turf |
How many sprinkler heads fit on one zone?
Add up the GPM of every head on a zone and keep the total at or below 80% of the flow your supply actually delivers. The 20% margin absorbs friction loss in the pipe and the pressure drop that shows up when a neighbour's system starts at the same time.
Measure the flow first, do not look it up. Run one outdoor faucet wide open into a 5-gallon bucket with nothing else running in the house, and time the fill: GPM = 300 ÷ seconds. A 20-second fill is 15 GPM. While you are out there, thread a hose-bib gauge on and read static pressure in PSI — most residential systems sit between 40 and 70 PSI, and spray heads want about 30 PSI at the nozzle. Step by step: how to measure water pressure, then how to turn it into a zone count.
| Measured flow | Usable (80%) | 15 ft half-circle sprays ≈1.85 GPM each | Standard rotors ≈3.1 GPM each |
|---|---|---|---|
| 6 GPM | 4.8 GPM | 2 | 1 |
| 10 GPM | 8 GPM | 4 | 2 |
| 14 GPM | 11.2 GPM | 6 | 3 |
| 20 GPM | 16 GPM | 8 | 5 |
Exact nozzle flow varies by manufacturer and by the pressure at the head, so treat the two right-hand columns as the starting point you check against your own nozzle chart. What does not vary is the arithmetic: heads that together ask for more than the supply can give will all run under-pressure, throw short, and leave gaps that look exactly like a spacing mistake. Split the zone instead — SprinklerMap totals the flow as you place each head and tells you when to.
Free vs. paid irrigation design software
Most irrigation design software built for professionals — CAD plug-ins, licensed sprinkler layout programs, contractor-grade planning suites — is priced and built for people designing dozens of properties a week. Installing and learning one of those tools to plan a single garden is overkill.
SprinklerMap takes the opposite approach: a free irrigation design tool that runs in any browser, with no license, no installation and no CAD experience required. Draw your garden, place sprinklers, and the app gives you the same core output a paid program would hand a contractor — head placement, coverage simulation, and a materials list — sized for a homeowner or small installer working on one property at a time.
If you're planning your own yard rather than running a landscaping business, there's no reason to pay for irrigation design software before you've even measured the lot. Start free, and see the full design — heads, zones, parts — before spending anything.
We also compared ourselves against the other free options, scored on the same four criteria and with the places we lose written down: 7 best free irrigation design software tools.
Before you open the tool
Three numbers decide the whole design, and none of them can be read off a drawing. Get them first and the layout takes ten minutes:
Available flow, in GPM
Bucket test at an outdoor faucet. It sets how many heads can share a zone — see flow and zone calculation.
Static pressure, in PSI
A hose-bib gauge, taken with nothing else running: how to measure water pressure.
What you are watering
Turf, beds and shrubs drink at different rates and belong on separate valves: hydrozones and mapping your zones.
Frequently asked questions
Is this sprinkler design tool really free?
Yes. Drawing your yard, placing heads, simulating coverage and generating the parts list are free and need no account. Automatic placement, the soil-absorption simulation and the PDF export ask for a free Google or Apple sign-in — a limit on the functions that cost the most server-side computation, not a paid tier.
Does it work in feet, GPM and PSI?
Yes. One tap switches the whole project to US units: every distance and throw radius reads in feet, flow in GPM, precipitation rate in inches per hour. Pipe is measured and listed by the foot. The drawing itself is stored unit-neutral, so you can switch back and forth without changing the design.
What spacing should I use between sprinkler heads?
Head-to-head: the spray from each head has to reach the next one, so spacing equals the throw radius. A 15 ft spray head goes on a 15 ft square grid, or about 17 ft on a triangular grid. Tighten that by 10-20% if you regularly water in wind above 5 mph. SprinklerMap draws the coverage arcs live, so the dry corners show up on screen instead of in the lawn.
How many sprinkler heads can I put on one zone?
Add up the GPM of every head on the zone and keep the total at or below about 80% of the flow your supply can actually deliver. At 10 GPM available that is roughly four 15 ft half-circle spray heads, or two standard rotors. SprinklerMap totals the flow as you place each head and flags the zone before it goes over budget.
How do I measure my available flow?
The bucket test: run one outdoor faucet wide open into a 5-gallon bucket and time how long it takes to fill. GPM = 300 divided by the seconds. Twenty seconds means 15 GPM. Do it with nothing else running in the house, and check static pressure with a $10 hose-bib gauge while you are out there — design on measured numbers, never on the ones printed in a catalog.
Can I use it on my phone?
Yes — it runs in any modern browser on Android, iPhone, iPad and desktop. GPS mode works especially well on a phone: walk your property line with it and the outline draws itself from your path, which beats a satellite trace when tree cover blocks the view.
What does the parts list include?
Sprinkler heads by type and count, main line length and diameter, lateral runs, one valve per zone and a filter recommendation — all quantities computed from your actual drawing, with pipe in feet. Prices are indicative reference figures, not a quote.
Design your sprinkler system now
Free, no account needed to draw. Feet, GPM and PSI. Start in seconds.