Please check my math...

Discussion in 'Starting a Lawn Care Business' started by griffinz, Apr 12, 2008.

  1. griffinz

    griffinz LawnSite Member
    Posts: 13

    OK,

    I wanted to compute the time needed to cut my back yard... thus finding the formula needed for my mower.

    I walked off the back yard using my Lufkin rolling tape measure... I guess that's what you call it.

    This gave my my back yard in sq ft.

    So:

    SqFt of my back yard = 12768

    1 sq foot = 2.29568411 × 10^(-5) acre

    Backyard sqft * 2.29568411 × 10(-5) acre = .2931129472 (this is the total acres of the back yard)

    mph of mower = 2.0

    cut width = 42

    acres cut per hour (at 80% efficiency) = ((mph*cutwidth)/120) so...

    ((2.0*42)/120) = .70 acres per hour

    Time it takes to cut back yard = (back yard acres/acres per hour) so...

    (.29/.70) = .42 hours to cut back yard so...

    .42*60 = 25 minutes to cut back yard.

    Is that right????:confused:

    Now, don't ask me to cut the back yard and time it!
     
  2. milsaps118

    milsaps118 LawnSite Senior Member
    Posts: 559

    You have a 42" mower that can only go 2.0 mph??? Either you have a really really bumpy backyard, or you are definitely not running at 80%. It should take you 10min TOPS to cut 12.7K sqft.
     
  3. griffinz

    griffinz LawnSite Member
    Posts: 13

    I think it cuts at 2.5 mph... its a residential Craftsman :laugh:
     
  4. milsaps118

    milsaps118 LawnSite Senior Member
    Posts: 559

    Well then if thats the case, 25min is about right.
     
  5. Dave_005

    Dave_005 LawnSite Senior Member
    Posts: 359

    2 MPH'S !!! Wow That is SLOW ! No Offence, but you can go faster than that with a push mower. 12,000 sq ft is a little over 1/4 acre 20 mins with a push mower and its done.
     

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