The conversion factors shown below are approximate and were taken from a variety of sources. When dealing with liquid or gaseous hydrocarbons, the actual volume, weight, mass, or heat content may depend upon a range of factors such as the specific gravity of the fluid, the amount (if any) of water entrained in the mixture, the temperature and pressure at which the measurements are taken, and other factors. Consequently, in many cases there is no single factor that can be used for conversion. The factors below may be used as rules of thumb and will work for general comparison purposes or calculations.