Lawn Irrigation Calculator — Embeddable Widget

Work Out Your Sprinkler Run Time

Units

Runoff on clay or slopes?

Weekly water target

Water per week (in, rain included)

Rain so far this week (in)

Watering days per week

Each zone runs once per watering day.

Zones

Zone 1 name
Lawn area (sq ft)
Sprinkler type
Zone flow (GPM, optional)
Zone 2 name
Lawn area (sq ft)
Sprinkler type
Zone flow (GPM, optional)

Add your zone flow to price the water from your own meter or sprinkler specs. Leave it blank and the gallons are worked out from the area and the depth applied.

Show the math

Minutes per week = (Weekly target − Rain) ÷ Precipitation rate × 60

Minutes per day = Minutes per week ÷ Watering days

Catch-can rate (in/hr) = Average depth (in) ÷ Test minutes × 60

Rate from flow (in/hr) = GPM × 60 ÷ (Area (sq ft) × 0.6234)

Gallons = Depth applied (in) × Area (sq ft) × 0.6234

All zones, each watering day

116 min

232 min per week, 2 days

Water per week

3,005 gal

About 13,020 gal per month

Front lawn
Each watering day
26 min
Per week
52 min
Water per week
1,135 gal
Rate 1.75 in/hr, water from area and depth.
Back lawn
Each watering day
90 min
Per week
180 min
Water per week
1,870 gal
Rate 0.5 in/hr, water from area and depth.

Watering 1.5 in this week (target minus rain). Minutes are rounded to whole minutes.