Two different methods are compared to estimate attitude in this study. These methods are Single Value Decomposition (SVD) solving Wahba's problem optimally and Algebraic Method using two vector measurements. Selected spacecraft data is used for orbit propagation. Magnetometer and Sun sensor are chosen for this work, also the mathematical models and the measurement models of these sensors are used for the actual value and the measurement values. Simulations are done and the covariance for two methods are calculated. According to the calculations comparison is made between these two methods. And as expected, it is seen that SVD method is more accurate than Algebraic Method.