ABSTRACT Optimization of hole cleaning remains one of the major challenges when planning and drilling high angle and extended reach wells. In this paper, a simple rig-site graphical technique is presented for determining hole cleaning requirements for a range of hole sizes. The method uses a set of charts which have been derived from a computer model based on both laboratory and field measurements. Access to the technology at the rig-site has been greatly improved by the development of the simplified charts. Examples are presented which illustrate how the charts can be applied to determine the influence of the major drilling variables on hole cleaning requirements. Mud rheology is shown to be a key variable for optimising hole cleaning in deviated wells. The charts can also be used to quantify the effect of hole enlargement which adversely affects hole cleaning. In addition, the paper discusses the detailed methodology behind the development of the charts from the original physically-based model. The charts presented in the paper are valid for the typical North Sea drilling conditions.