Snow Weight - Area (polygon)

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Equation / Last modified by KurtHeckman on 2016/12/13 15:11
KurtHeckman.Snow Weight - Area (polygon)

The Weight of Snow on a Polygon calculator computes the approximate weight of snow on an POLYGON area (e.g. deck).  The inputs are the dimensions of the polygon covered (number of sides of the polygon and the radius), the depth of the snow, and the type of snow (based on standard snow types).  SnowWeightAreapolygon-illustration.png Geometric Polygon 
INSTRUCTIONS: Choose your preferred units and enter the following:

  • (n) The number of sides of the polygon
  • (r) The radius of the polygon (from the center to any apex).
  • (d) The depth of the snow
  • (sT) Choose the type of snow from the list.

The Weight of the Snow is returned in kilograms.  However this can be automatically converted to other weight and mass units (e.g. pounds or tons) via the pull-down menu.

To compute the Volume of Water in an Area of Snow, CLICK HERE.
To compute the Weight/Mass of Snow on an Area, CLICK HERE.
To compute the Weight of Snow on a Rectangular Area, CLICK HERE.
To compute the Weight of Snow on a Roof, CLICK HERE.


Snow Water Equivalent (SWE) is the product of snow depth and snow density. It can be presented in units of either kg/m2 or m:

SWE (`(kg)/(m^2)`) = snow depth (m) x snow density (`(kg)/(m^3)`)
 SWE (m) = snow depth (m) x snow density (`(kg)/(m^3)`) / water density (`(kg)/(m^3)`)

 You can calculate snow depth from SWE if you know the density of the snow.  Od course, density of snow can range anywhere from 5% when ambient air temperature is 14 F, and can range up to 20% if the temperature is 32 F.

The snow density will increase after the snowfall due to gravitational settling, packing, wind effects, melting and refreezing.

Type of snow or icedensities (kg/m³)
New snow (immediately after falling in calm)50-70
Damp new snow100-200
Settled snow200-300
Depth hoar100-300
Wind packed snow350-400
Firn   (granular snow)400-830
Very wet snow and firn700-800
Glacier ice830-917

The equation will use a median value for the ranges in the density value column.