In this paper, figures of merit describing the performances of infrared (IR) bolometer sensor such as thermal response time (τ τ), responsivity, detectivity (D*), noise equivalent power (NEP) and noise equivalent temperature difference (NETD) are estimated using numerical simulations. The proposed model is based on the analytical formulas from Frank Niklaus, et.al. Using this model, we have evaluated the performance of two-legged, uncooled infrared bolometer sensor with 52×52 μm 2 and 35×35 μm 2 pixel-pitch size. The bolometer sensors were fabricated by Institut National d'Optique (INO), Canada and National Chung-Shan Institute Science of Technology (NCSIST), Taiwan. Test structures including uncooled vanadium oxide bolometer FPAs were fabricated at INO to verify the agreement between the simulated and experimental data. The performance model was used at NCSIST to evaluate the improvements on design and fabrication of bolometer FPAs with pixel pitch varying form 35 μm to 52 μm.