The amount of snow that equals an inch of rain depends on the density of the snow. A general rule of thumb is that 1 inch of rain is roughly equivalent to 10 inches of snow, but this can vary significantly depending on the type of snow. Wet, heavy snow can have a ratio of 3 or 4 inches of snow to 1 inch of rain, while light, fluffy snow may have a ratio of 30 or 40 inches of snow to 1 inch of rain.