The Snow Pack to Liquid Water calculator computes of the volume of liquid water contained in snow pack defined by area, depth and snow type.
INSTRUCTIONS: Choose units and enter the following:
Liquid Water Volume (V): The volume is returned in acre-feet, gallons and liters. However, these can be automatically converted to compatible units via the pull-down menu.
The Snow Pack to Liquid Water calculator computes the rough volume of water stored in snow. First, it computes the volume of snow, and then computes the volume of water content by multiplying the volume of snow by the density of water in the snow based on the type of snow. This gives you the mass of the liquid water, which is converted easily into volume units such as acre-feet, gallons and liters. 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. The table contains a generally accepted range of density (kg/m3) for different types of snow. The equation will use a median value for the ranges in the density value column.
Type of snow or ice | (kg/m3) |
Fresh New snow | 50-70 |
Damp new snow | 100-200 |
Settled snow | 200-300 |
Depth hoar | 100-300 |
Wind packed snow | 350-400 |
Firn (granular) | 400-830 |
Very wet | 700-800 |
Glacier ice | 830-917 |
Rain/Melt | 997 |
The areas entered can be small for things such as patios and roofs, and they can be large like a county.