Free calculators
Lawn calculators
The same maths that runs inside the lawn app, one sum at a time. Nothing to install, nothing to sign up for, and nothing you type here leaves your browser.
Fertiliser dose
How much of that bag to put down, worked from the N percentage on the label
Lawn area
Add up odd-shaped lawns from rectangles, triangles and circles
Sprinkler run time
Catch cup test, so you water to a depth instead of guessing at minutes
Topdressing and sand
How many cubic metres, litres or bags for the depth you want
Which grass is it?
Six questions about your lawn, narrowed down to the most likely type
Why the app is better than any of these
A calculator does one sum and forgets. The app remembers your lawn, counts the nitrogen you have already put down this year, and tapers the last few doses so you cannot accidentally overfeed. It also tells you what is due. Free, no account, works offline.