How do I convert volumes of liquids and gases into weight (pounds)?
Only the weight of the substance needs to be reported and not the weight of the container. Most gases and liquids are sold by the pound, and these weights should be noted on the label. If so, then the weight can easily be estimated by multiplying the weight of a full container by the fraction of the volume remaining. If the liquid is not labeled in pounds, then you can calculate its weight by multiplying the volume of the liquid by its density. The density (mass per unit volume) should be noted on the MSDS. If not, then simply estimate the weight by the density of water. Be careful with your units of measure (gallons, liters, pounds, kilograms). If the weight of the gas is listed on the cylinder’s label, base your calculation on this measure. You can obtain the “tare weight” (the weight of the cylinder without gas) either from the label or by subtracting the listed weight of the gas from the total weight of a full cylinder. Knowing the tare weight, you can chart the gas remaining in th
