Just in case you are trying to fathom out some markings on a plan somewhere….

The Formula is as follows…… degree of slope X 1.746 cm X 1 Metre of run equals rise in centimetres ( or negative FALL)

e.g. (DDO8)  2.5 degrees over an 8 meter span = 2.5   X 1.746 cm X 8 metres = 34.92 Cm per meter, or 0.3492 m  rise, over a meter sideways.

trigonometry rise

The gradient (also known as slope) of a line is defined as:     gradient =  vertical rise  / horizontal run

Say a 2 meter rise, over an 8 meter run is  2/8 = 1/4 = .25m  or could be referred to as “1 in 4.”

3 Responses to “DEGREES OF SLOPE TO FALL CALCULATOR – Including Gradient”

  1. Talford says:

    Thanks for the information. I have noticed that most of the planning schemes throughout Melbourne express fall in degrees which is often confused with percentage of gradient. The following condition is included in the Manningham Planning Scheme in regard to building height limit applicable to the DDO8;
    “9 metres, unless the slope of the natural ground level at any cross section wider than eight metres of the building is 2.5 degrees or more, in which case the maximum building must not exceed 10 metres”.
    Using your formula the above is near enough to a fall of .350m in 8m.

  2. Danil says:

    thanx, but very little about roof pitch in degrees

  3. Russ says:

    Nice approximation … but remember it is an approximation. The error increases with angle (-1% error at 10 degrees, -10% error near 30 degrees, -20% error near 45 degrees).

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