Irrigation System Calculator: Estimate Water Needs & Costs

Calculate irrigation system water requirements and total cost for your garden or landscape. Supports metric & imperial units and multiple currencies.

m²/ft²
mm/week or in/week

Enter your measurements above to see the results.

How to Use This Calculator

Use our irrigation system calculator to estimate the water requirements and total installation and running costs for your garden or landscape. Simply enter your area, water needs, and costs to get accurate results in both metric and imperial units, with full cost breakdowns in your chosen currency.

How it is calculated

Convert area and water requirement to litres or gallons based on unit system. Calculate water per cycle and total weekly usage. Installation cost is area times install cost per area. Weekly water cost is weekly usage divided by 1000 (or 264.172 for gallons) times water cost per unit.

Worked example

Inputs: unitSystem = Metric, area = 100 m², waterPerArea = 25 mm/week, cyclesPerWeek = 3, installCostPerArea = 5 (currency), waterCostPerUnit = 2 (currency). Water per cycle = (100 * 25) / 3 = 833 L. Weekly water usage = 833 * 3 = 2500 L. Install cost = 100 * 5 = 500. Weekly water cost = (2500 / 1000) * 2 = 5.

How to Use the Irrigation System Calculator

Enter your garden or lawn area, preferred unit system, and typical weekly water requirement. Add your installation and water costs to get a complete estimate. The calculator provides water per cycle and total weekly figures, making it easy to plan your irrigation setup.

Why Accurate Irrigation Calculations Matter

Properly sizing your irrigation system ensures healthy plants and efficient water use. Over- or under-watering can damage landscapes or waste resources. This calculator helps you match system capacity to your actual needs, saving money and supporting sustainability.

Choosing Between Metric and Imperial Units

The calculator supports both metric (m², mm, L) and imperial (ft², in, gal) units. Toggle the unit system to match your local standards. All results and cost calculations adjust automatically for your selection.

Understanding Irrigation System Costs

Installation costs can vary based on system type, area, and region. Enter your estimated cost per area to get a reliable total. Ongoing water costs are also calculated, helping you budget for both setup and regular use.

Frequently Asked Questions About Irrigation Systems

Find answers to common questions on cost, water usage, types of systems, and installation. Use the calculator to tailor estimates to your specific landscape and local prices.

Common Questions

How much does an irrigation system cost to install?

Installation costs vary widely based on area, system type, and location. Typical home garden systems range from £500–£2,500 ($700–$3,500), but you can estimate your specific cost using this calculator by entering your area and installation cost per unit.

How much does a sprinkler system cost?

Sprinkler system costs depend on the size of the area, the complexity of the setup, and regional labour rates. Use the calculator to get a tailored estimate by inputting your area and installation cost per square metre or foot.

How much water does an irrigation system use?

Water usage depends on the area covered and the amount of water applied per week. The calculator estimates total weekly water requirements based on your inputs, helping you plan for efficient use and budgeting.

How many types of irrigation systems are there?

There are several main types: drip irrigation, sprinkler systems, surface irrigation, and subsurface irrigation. Each has different installation and operating costs, which can be factored into your calculations.

How much does it cost to run an irrigation system weekly?

Weekly running costs are mainly determined by water usage and the price of water in your area. The calculator estimates your weekly water cost based on your area, water requirement, and your local water price.

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