Drip System Flow Calculator

Balance emitters, zones, and pressure for efficient watering. Instantly convert units and estimate runtime daily. Download reports, verify capacity, and avoid dry spots today.

Calculator inputs

Count the points needing irrigation.
Typical: 1–4 emitters per plant.
Use the emitter’s rated flow at working pressure.
Assumes one zone runs at a time.
%
Covers small leaks, filter loading, or growth.
%
Lower values increase required watering time.
Use crop stage, weather, and soil as guidance.
Split watering to reduce runoff and stress.
Often 8–15 psi for many drip emitters.
Positive only; downhill does not raise demand here.
Include filter, valves, mainline, and laterals.

Example data table

Use this sample to understand typical inputs for a medium garden bed.

Scenario Plants Emitters/Plant Emitter Flow Zones Efficiency Result (Per Zone)
Vegetable bed 60 2 2.0 L/h 3 90% ≈ 80 L/h
Mixed shrubs 30 4 1.6 L/h 2 85% ≈ 96 L/h
Raised planters 20 1 2.0 gal/h 1 95% ≈ 151 L/h

Formula used

Total emitters = Plants × Emitters per plant

Total system flow (L/h) = Total emitters × Emitter flow (L/h)

Flow per zone (L/h) = Total system flow ÷ Zones

Recommended source flow (L/h) = Flow per zone × (1 + Safety factor)

Runtime per event (minutes/zone) = (Daily need ÷ Efficiency ÷ Events ÷ Zones) ÷ (Flow per zone) × 60

How to use this calculator

  1. Enter your plant count and emitters per plant.
  2. Select the emitter’s rated flow and unit.
  3. Set zones as you will run them, one at a time.
  4. Add safety factor to cover real-world losses.
  5. Enter daily water need and efficiency for runtime.
  6. Optionally include pressure, elevation, and friction loss.
  7. Press Calculate flow, then download CSV or PDF.

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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.