Garden SurveyorIrrigation Systems Calculator
Size a garden irrigation system from a bucket-flow test: converts supply flow into litres/min, applies friction loss, splits the system into hydraulically viable zones and returns a priced bill of materials.
What you're watering — biases the system recommendation.
The distribution method to size and cost.
Mains pressure at rest (3.0 Bar ≈ 45 PSI is typical UK).
Time your outside tap filling a standard 10-litre bucket — sets available flow.
1 advanced input hidden. Switch to Advanced to fine-tune.
- Total area (m²)
- 32m²
- Available flow rate (LPM)
- 30
- Zones required
- 2
- System flow demand (LPM)
- 36.8
- Working pressure (Bar)
- 2.9
2
Zones required
30 LPM
Available flow
Moderate
Complexity
⚠️ Inadequate Flow Rate for Single Zone Run. Automatically splitting system into 2 independent zones using a multi-way solenoid manifold.
Run-time schedule
Optimised zone order
Each bar is when a zone runs across the morning. Zones already run at the best time, so nothing was moved.
- 1Zone 1kept6:00 am – 6:07 am
- Already clear of the restricted band — kept in place
- Run time preserved at 7 min — weekly volume unchanged
- 2Zone 2kept6:07 am – 6:14 am
- Already clear of the restricted band — kept in place
- Run time preserved at 7 min — weekly volume unchanged
2 zones run back-to-back from 6:00 am (14 min total).
Best watered early morning (5–7 am). 2 zones run in sequence. Reduce after rainfall and outside the growing season.
Bill of materials
25 mm MDPE supply pipe
Main run + distribution (25 mm)
£48
23 m @ £2
Porous drip-line
Grid @ 0.35 m spacing
£147
92 m @ £2
Compression elbow / tee fitting
1 per 6 m of rigid pipe
£10
4 each @ £2
Multi-way solenoid manifold connector
One manifold port per zone
£56
2 zone @ £28
Hold-down pipe stakes (bulk pack of 50)
Pin runs to ground
£28
4 pack @ £7
Joining clips (bulk pack)
Secure connections
£6
1 pack @ £6
PTFE thread tape
Seal threaded joints
£3
1 roll @ £3
Indicative estimate
Indicative UK retail (ex VAT & delivery). Trade prices refine these in the quote editor.
This app provides general UK guidance and material estimates only. It is not legal, planning, engineering or building-control advice. Always confirm requirements with your local planning authority, building control, utility providers, manufacturers or qualified professionals.