Lawn growth calculator

How fast is this lawn growing — and what does that mean for cutting?

Measure the grass twice a few days apart. The calculator works out how fast it's growing, then shows what different cut heights would leave you with and how many days you can go before the next mow — keeping it under the heights your customer cares about.

1 — The property and your mowing schedule

Property name

Grass type

Lowest mower cut height

Highest mower cut height

How often you mow now

How often you'd like to mow

2 — Measure how fast it's growing

Height right after the last mow

Grass height now Measure the typical leafy height — ignore the odd tall seedhead.

Days since the last mow

Growing speed right now

Weather lately

How this works: the growth rate comes straight from your two measurements — (height now − height after last mow) ÷ days. The projection ahead follows that measured rate, nudged by how fast things are growing right now. The shaded band on the chart shows how much lawn growth normally swings with heat and moisture — it's not measurement error. Saved history for a property, when you have it, is used instead of the projection.

Optional: set the growing speed from local weather

Look up recent temperature and rain to get a suggested growing speed for the field above. Free, no account. When you use this, a location (a town, ZIP, or your device's coordinates) is sent to the Open-Meteo weather service to fetch conditions — nothing is stored on our servers, and this is optional. It only suggests a value; you decide whether to apply it.

3 — Height limits the customer cares about

Highest you can cut to and still look good

Tallest the lawn should get between mows

These two heights bound the answer: the tool won't suggest a cut taller than the first, and it flags when the lawn would grow past the second before your next visit.

4 — What to do

Suggested cut height——

Lawn height, current spacing——

Lawn height, longer spacing——

Longer spacing — doable?——

Confidence——

—

Growth per day—

How much you cut off last time—

How much you'd cut today—

Room under the limit—

Extra slowdown needed—

Notes

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A longer interval is only a projection until you've actually saved a visit at that spacing for this property. Test it before you sell it.

5 — Charts

Canopy height rising day by day from the selected cut, at your measured growth rate. The shaded band is how much growth typically varies with temperature and moisture for the environment you selected; the red line is the tallest canopy the customer accepts.

Deck	Role	Fresh-cut	Current return	Target return	Target range	Target gap	Target growth	Repeated removal	Current finish	Target finish	Current load	Target load	Evidence	Confidence	Validation

6 — Save this visit (builds a record for the property)

Each saved visit teaches the tool this property. Once you've logged a few, it uses your real measured history for this lawn instead of the generic projection. If you ran the weather lookup above, the recent temperature and rain are saved with the visit too — building a growth record you can later export.

Visit date

Cut height used

Grass height on arrival

Height after the previous mow

Days since the previous mow

Notes (optional)

Growth by cut height & spacing

Prior cut	Interval class	Environment	Median normalized growth/day	Median interval growth	Median return	Observations	Range	Confidence

Saved visits

Date	Prior cut	Current cut	Arrival	Days	Class	Growth/day	Environment	Notes	Delete