The assessment of lower limb oedema almost always involves measuring leg volume, and the gold-standard for this is the water displacement technique. As it is not very practical to use in a clinical routine, physicians prefer indirect methods such as anthropometric or bioimpedance measurements. In the case of "non-pitting" leg oedema, i.e. where the presence of oedema is not obvious, it may be challenging to estimate changes in leg volume using these methods separately. The combination of these two methods, however, gives interesting results, such as a new composite parameter that is much more robust and efficient than commonly used parameters.Clinical Relevance- This study demonstrates the benefit of using a composite anthropometric-impedimetric parameter to predict water displacement variations in the leg over the course of a day, rather than using parameters based solely on anthropometry or impedance. Our new parameter (C²-A²)/R0 showed a robust r² value of 61%, which is more than twice the r² values obtained using other simple or composite parameters.