<p>In this study, the fracture characteristics of silica filled Styrene-Butadiene Rubber composites are studied under mixed-mode loading. A single edge notched specimen is analysed with varying crack inclination angle and notch to width ratios. The Ogden Material Model of fourth-order is used to simulate the fracture behaviour due to its high efficacy. J-integral, a measure of energy released per unit increase in crack surface area and the non-dimensional parameter geometry factor, a calibration term for different kinds of specimens are calculated. It is observed that the geometry factor is not only dependent on the notch to width ratio and crack inclination angle but also on the applied stretch. It is evident through results that the geometry factor decreases by approximately 50% when the applied stretch increases from 1.04 to 1.4. It is observed that as the crack inclination angle increases from 0° to 15° the decrease in geometry factor is only marginal, 5.5% on average. The subsequent decreases in its values for 15° increments in crack inclination angle (15° to 75°) get progressively larger at 18.8%, 27.4%, 42% and 53% respectively. Further, it is observed that increasing the notch width ratio from 0.2 to 0.6 leads to approximately 70% increase in geometry factor. However, a further increase from 0.6 to 0.8 notch width ratio leads to a 26% decrease in the values. Geometry factor is found to vary non linearly with all major parameters (applied stretch, notch to width ratio and crack inclination angle). Finally, polynomial based empirical relations are developed for the geometry factor using a non-linear regression code developed in MATLAB. The cubic relation successfully matches the geometry factor values obtained from finite element analysis.</p>