HowMuchIt / Lawn water
How much water does my lawn need?
About an inch a week, and the rain counts. The calculator turns that inch into gallons for your lawn, and, with a quick tuna-can test, into minutes on the sprinkler.
Work out your lawn water
Most lawns need about 1 inch a week, rain included (guides give 1 to 1.5). One inch on 1,000 sq ft is about 620 gallons.
The tuna-can test
Set several empty tuna cans, or any straight-sided cans, around the lawn. Run the sprinkler for a set time, say 20 minutes, then measure the water in each can and average it. Now you know how many inches your sprinkler puts down in 20 minutes, and how long it takes to reach the inch you want. Type both numbers and the calculator does the division.
Deep, early, less often
Water deeply and less often, rather than a little every day: deep watering grows deeper roots, and light daily watering keeps them shallow. Early morning is the best time; in the heat of the day much of the water evaporates before it soaks in. Sandy soil drains fast and needs watering more often than heavier soil.
Questions people ask
How many gallons for a 5,000 sq ft lawn?
About 3,100 gallons for an inch.
Should I water every day?
No: deeply and less often grows deeper roots.
What time should I water?
Early morning.
Good to know
- Most lawns need about 1 inch of water a week, and rain counts toward that inch.1,2,3,4
- Many lawn guides give a range of 1 to 1.5 inches of water a week, counting rain.5,6
- One inch of water on one square foot is about 0.62 gallons, so 1 inch on 1,000 square feet is about 620 gallons.2,7,8
- Tuna-can test: set several empty tuna cans or other straight-sided cans around the lawn, run the sprinkler for a set time such as 20 minutes, then measure the water in each can and average it.2,3,5,9
- Use the can test to set the run time: time how long the sprinkler takes to fill the cans to the depth you want.1,3,6
- Water deeply and less often rather than a little every day; deep, infrequent watering grows deeper roots.2,3,5,9
- Light daily watering is not recommended: it leads to shallow roots.1,5,9
- Early morning is the best time to water a lawn.2,3,5,9
- Avoid watering in the heat of the day, when much of the water evaporates before it soaks in.1,5,9
- Sandy soil drains fast and needs watering more often than heavier soil.2,3,5
How we checked this page
Checked on October 27, 2026. We kept a fact only when two independent publishers agree, and each one is numbered to its sources below. Where sources give different numbers, we keep only what they share. We never write a price. This page was written with an AI assistant and checked against the sources below.
Sources
- Watering Tips, US EPA WaterSense
- How Often Should I Water My Lawn?, LawnStarter
- How Often Should A Lawn Be Watered?, Clemson Cooperative Extension Home and Garden Information Center
- Irrigation for a Healthy Lawn, N.C. Cooperative Extension, Carteret County (NC State University)
- How Long Should You Water Your Lawn?, Bob Vila
- How Often Should You Water Your Lawn in the Summer?, Lawn Love (LawnStarter)
- Supplemental Water Requirements (Plant Irrigation Needs), Plant Select
- Water is limited. Save some today! (conservation tip card), Texas Water Development Board
- Irrigating home lawns (Turf Fact Sheet 2011a), University of Nebraska-Lincoln Extension