Garden Watering Calculator

About this calculator

Most vegetable and flower beds need about 1 inch (2.5 cm) of water per week — from rain or irrigation combined — and this calculator converts that depth guideline into an actual volume of water (gallons or liters) by multiplying it by your bed's area, since a shallow layer over a large area adds up fast.

Gardeners use it to avoid both underwatering, which stresses roots and cuts yields, and overwatering, which wastes water and can promote root rot and fungal disease — knowing the volume target for a specific bed also makes it easy to time a drip line or soaker hose instead of guessing by feel.