Mud weight[1] as described in the oilfield is the density (weight) of the drilling fluid and is normally measured in pounds per gallon (lbm/gal) or (ppg). In the field it is measured using a mud scale or mud balance.

In conventional drilling fluids, barite is used to incresase the density (weight). Though other additives such as halite (salt) or calcium carbonate can also be used. Mud weight can be decreased by dilution or solids control equipment such as an industrial centrifuge .