Estimate how much water your garden needs each week from its area, plant type and climate, using a simple evapotranspiration approximation.
100% Local
How to Use the Garden Water Usage Estimator
Enter your garden area in square metres. If you only know how many plants you have, leave the area blank and enter the plant count instead — the tool assumes about 0.25 m² per plant. Pick the plant type and the general climate, then press Calculate. Use Clear to reset the form.
How the estimate is built
It starts from a weekly reference evapotranspiration of about 15 mm in a cool climate, 25 mm moderate and 35 mm hot.
Each plant type has a crop coefficient: vegetables and lawn about 1.0, flowers 0.9, herbs 0.8, shrubs 0.6 and succulents 0.3.
One millimetre of water over one square metre equals one litre, so litres = area × reference ET × crop coefficient.
Real use varies with wind, humidity, soil and mulching, so treat the figure as a starting point and adjust from what you observe.
Features
Estimates weekly and daily water use in litres
Covers vegetables, flowers, lawn, shrubs, herbs and succulents
Accepts garden area or plant count
Works on desktop, tablet and mobile with no sign-up
All processing runs locally in your browser. Your data is not uploaded to any server.