Irrigation Water Cost Calculator
What does watering your garden really cost?
Enter your watering setup and we will show the real water use and cost per session, per month and per season — then price the same lawn on sprinkler, drip and hose, so you can see the cheapest way to water.
- Sprinkler vs drip vs hose
- Water bill or pump pricing
- No signup to use it
1 Your watering
2 Your water rate
Advanced: method efficiency
Costs you
The same lawn, every method cheapest first
| Method | Water per month | Cost per month | Cost per season | Difference |
|---|
Drip-saving and hose figures are editable estimates — see Advanced. Costs are for comparison, not a quote.
What this calculator does
It works out how much water your lawn or garden really uses — per session, per month and per season — and what that water costs you, from your water bill or from running a pump. Then it prices the SAME lawn on sprinkler, drip and hand-hose watering, so you can see the cheapest way to water.
The formula
Water per session = flow rate × minutes
- A sprinkler at 4 gallons a minute for 30 minutes = 120 gallons.
Water per week = per session × sessions per week. Cost = water used × your rate (per 1,000 gallons, per cubic metre, or pump electricity: hours × pump kW × tariff per kWh).
Standard agronomy rule: 1 inch of water over 1 square foot = 0.623 gallons. So a 5,000 sq ft lawn getting 1 inch a week needs 5,000 × 0.623 = about 3,115 gallons a week.
Getting an accurate answer
- Measure your real flow: time how long it takes to fill a bucket, then divide. Labels and box claims are often optimistic.
- Use your real water rate — check a recent bill; tiered rates mean the last gallons cost more than the first.
- Count only the weeks you actually water, not the whole year.
Frequently asked questions
How much does it cost to water a lawn? It depends on lawn size, flow rate and your water price. A 5,000 sq ft lawn watered 3 times a week at 4 GPM for 30 minutes uses about 1,440 gallons a week — at $3.00 per 1,000 gallons that is roughly $17 a month in the watering season.
How many gallons does a sprinkler use per hour? A typical garden sprinkler flows 2–5 gallons per minute, so 120–300 gallons per hour. Measure yours with the bucket test for an exact number.
Is drip irrigation cheaper than sprinklers? Yes — drip puts water straight at the roots with almost no evaporation or overspray, typically using about 50% less water than sprinklers for the same plants. The saving shows up directly on your water bill.
How much water does a lawn need per week? The standard target is about 1 inch per week, including rainfall — roughly 0.623 gallons per square foot. Deep, infrequent watering beats a daily sprinkle for root growth.
Is watering with a pump cheaper than tap water? Often yes, if you have a well or free water source: you only pay the pump's electricity. A 2 HP pump (1.49 kW) at $0.18/kWh costs about $0.27 per hour of pumping. Compare both modes in the calculator.
Does watering at night save money? It saves water rather than money directly: less evaporation means you can run shorter sessions for the same 1 inch, which is what your meter (or pump) charges you for.