Watering Needs Calculator
How many gallons your garden bed needs each week.
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Tools & Calculators
Every tool in one place. Search or pick a category, then start doing the math.
Watering & Irrigation — 16 calculators
New Drip Irrigation Planner
Emitters, zone flow and weekly run time for drip lines.
Use ToolNew Rainwater Harvesting Calculator
Gallons your roof harvests per rain inch, and barrels needed.
Use ToolNew Bucket Test Flow Calculator
Measure your spigot's real GPM with a bucket and a stopwatch, then size a drip zone.
Use ToolNew Vacation Watering Calculator
Will your plants survive the trip? Size a reservoir, mulch credit and ollas against days away.
Use ToolNew Rain Barrel Deck Load Check
Is a full rain barrel safe on your deck, balcony or patio? PSF vs surface capacity.
Use ToolNew Soaker Hose Run Time Calculator
How long to run a soaker hose to apply a target depth of water to a bed.
Use ToolNew Sprinkler Application Rate Calculator
How many inches per hour your sprinkler delivers and how long to run it for a target depth.
Use ToolNew Garden Watering Cost Calculator
Gallons and dollars a season of watering will cost you, by water source, from bed area, depth, and watering frequency.
Use ToolNew Drip Flow Rate Calculator
Converts emitter gph into gpm and lpm, totals a zone, and times the run needed to apply a chosen water depth.
Use ToolNew Rain Barrel Calculator
How many barrels and how much storage your roof can fill, sized against weekly garden demand from area and rainfall.
Use ToolNew Crop Water Requirement Calculator
Weekly and seasonal irrigation gallons a planting needs, from area, reference evapotranspiration minus rainfall.
Use ToolNew Irrigation Scheduling Calculator
Soil-aware watering schedule: allowable depletion depth, refill volume in gallons and days between waterings at your management deficit.
Use ToolNew Rain Garden and Swale Calculator
Size a rain garden or swale from roof runoff and soil infiltration, with required bed area, overflow, drain time and a planting count.
Use ToolNew Drip and Spray Irrigation Install Cost Calculator
Price a drip or micro spray irrigation install as materials, zoning and trenching, DIY against contractor, with payback years.
Use ToolNew Pot Drainage and Watering Frequency Calculator
Size the drainage holes a pot needs and work out the watering interval, weekly gallons and soak depth for a plant and pot material.
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