Snowfall Calculator — Liquid Equivalent and Snow Ratio

Estimate new snowfall from a liquid-water equivalent and a snow-to-liquid ratio that you supply. The liquid amount is the water contained in the portion of precipitation falling as snow. Results are given in centimeters, inches and millimeters so you can compare scenarios without changing the underlying depth.

How to use this tool

1. Enter the liquid equivalent assigned to snow, excluding rain or other precipitation.
2. Choose millimeters, centimeters or inches for that liquid depth.
3. Enter the snow-to-liquid ratio; 10 means ten units of snow depth per unit of water depth.
4. Compare the converted depths and repeat with another ratio if you need a scenario range.

Formula

New snow depth = liquid-water-equivalent depth × snow-to-liquid ratio

Depth units must match before multiplication. One inch is exactly 25.4 millimeters and one centimeter is 10 millimeters. The accepted ratio range is 1:1 through 100:1; this is an input range, not a forecast of the actual ratio.

Example

A liquid equivalent of 0.5 inches with a 12:1 ratio gives 6 inches, or 15.24 centimeters, of new snow before subsequent changes. The calculation does not say whether that liquid amount or ratio will occur.