Irrigation Water Needs
Estimate weekly gallons of water a garden bed needs.
About Irrigation Water Needs
One inch of water on a square foot is roughly 0.623 gallons, so multiplying bed area by the weekly depth gives the watering volume. Measuring water by depth rather than by time makes plants self-sufficient and prevents both drought stress and root rot from overwatering.
Formula
Irrigation Water Needs
Gallons = area x water depth x 0.623 (one inch on one sq ft)
- water depth
- Mulching reduces how much the soil actually needs
Worked example
With the default values below, Irrigation Water Needs returns Gallons per Week of 124.6. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Bed areaminimum 0 sq ft
- 200 sq ft
- Weekly water depthminimum 0 in
- 1 in
Results
- Gallons per Week
- 124.6 gal
- Liters per Week
- 471.7 L
- Gallons per Day
- 17.8 gal
Step by step
- 1Values used
- 2Irrigation Water Needs
- 3Gallons per Week= 124.6 gal
- 4Liters per Week= 471.7 L
- 5Gallons per Day= 17.8 gal
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Irrigation Water Needs calculated?
Gallons = area x water depth x 0.623 (one inch on one sq ft) One inch of water on a square foot is roughly 0.623 gallons, so multiplying bed area by the weekly depth gives the watering volume.
Why does Irrigation Water Needs matter?
Measuring water by depth rather than by time makes plants self-sufficient and prevents both drought stress and root rot from overwatering.
What values do I need to enter?
This calculator takes 2 inputs: Bed area, Weekly water depth. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.