Sprinkler output and watering schedule calculator

Catch-can calculator

Run the zone, measure water in matching cups or cans, then enter each depth in inches. Use zero only for a cup that truly caught no water.

Test minutes Weekly target inches Recent rainfall inches Watering days allowed Cycles per watering day Zone name

Cup 1 Cup 2 Cup 3 Cup 4 Cup 5 Cup 6

Average catch

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Sprinkler output

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Runtime per day

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Runtime per cycle

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Enter at least one catch depth and a test length to calculate output.

Formula

Use measured water depth, not sprinkler label flow.

Average catch depth = total measured cup depth / number of cups

Sprinkler output in inches per hour = average catch depth / test minutes x 60

Net weekly irrigation target = weekly target inches - recent rainfall inches

Minutes per watering day = net weekly target / sprinkler output x 60 / watering days

If runoff starts before the daily runtime is complete, split the day into multiple shorter cycles and let water soak in between cycles.

Lawn profile

Item	Notes
Zone name
Grass type	Cool-season / warm-season / mixed / unknown
Soil type	Sandy / loam / clay / compacted / unknown
Sun and shade	Full sun / part shade / heavy shade
Slope or runoff risk	Flat / mild slope / steep / hardscape nearby
Sprinkler type	Spray / rotor / impact / drip / mixed
Local watering rules

Catch-can worksheet

Cup	Depth in inches	Notes
1
2
3
4
5
6
Average

Schedule planner

Assumption	Your number
Test run length in minutes
Sprinkler output in inches per hour
Weekly target inches
Recent rainfall inches
Net irrigation target
Watering days allowed
Cycles per watering day
Minutes per watering day
Minutes per cycle

Adjustment notes

• Clay soil, compacted soil, slopes, and hard edges often need shorter cycle-and-soak runtimes to reduce runoff.
• Sandy soil may need smaller, more frequent applications because water drains quickly.
• New seed or sod follows establishment instructions first; this weekly planner fits established turf better.
• Brown spots can come from drought stress, poor coverage, disease, insects, compaction, or mower stress. Do not treat every brown area as a runtime problem.
• Watering restrictions, drought stages, rain sensors, and smart-controller rules override a generic schedule.

Retest log

Date	Zone	Average catch	Output inches/hour	Nozzle or pressure changes	Follow-up