Spread Rate (by Mass)

The spread rate of a substance is a measure of how much of it there is covering a unit area. The 'how much' can be measured by volume or by mass. The S I compatible unit of spread rate by mass is kilograms/square metre. It is also a measure of area density (mass/unit area) and is similar to - but not the same as - pressure, which is force/unit area. For the rainfall conversions a density of 1 kg/liter has been assumed. To change any of these other units of spread rate into their equivalent values in kilograms/square metre use the operation and conversion factor given. Those marked with # are exact. Other values are given to an appropriate degree of accuracy. The conversion for rainfall assumes a density of 1 kg/liter which is accurate enough for all practical purposes.

grams/sq.centimetre x 10 #

grams/sq.metre divide by 1000 #

inches of rainfall x 2.54

kilograms/hectare divide by 10 000 #

kilograms/sq.centimetre x 10 000 #

milligrams/sq.metre divide by 1000 #

millimetres of rainfall 1

kilograms/sq.metre 1

ounces/sq.foot x 0.305 152

ounces/sq.inch x 43.942

ounces/sq.yard divide by 49.494

pounds/acre divide by 8921.791