This research considers the effect of in-plane rotation angles on the structural performance of Cross Laminated Timber (CLT) panels. In the interest of expanding the application of CLT to folded or freeform structures, rectangular CLT panels are likely to be divided into irregular geometries, in which case the loading will be applied at an intermediate orientation between the longitudinal and transverse panel axes. Such a loading condition is not accounted for in the existing analytical methods for dimensioning and designing with CLT. An analytical method is proposed which hybridizes the Shear Analogy method with Hankinson’s equation, allowing a designer to determine the effective stiffness of a CLT panel with any layup and at any in-plane rotation angle. An analytical study, followed by implementation with 3D parametric Finite Element Modelling and an experimental investigation, is used to evaluate this method. Results show that cross-grain/in-plane rotation has considerable effect on strength and stiffness of CLT panels with fewer than 5 laminations.