A snapshot of power system network conditions can be captured by a state estimation algorithm. State estimation is a computational technique for an electrical power system Operation, supervision, and inspection. It empowers the calculation of the power flows of the electrical power system which are not observed or not directly measured. State estimation is a computer program that detects isolates and eliminates incorrect or bad measurement data and estimates the accurate state. The magnitudes of bus voltage and phase angle are the state variables for an electrical power system. This paper outlines Weighted Least Square (WLS) estimation techniques and simulated estimation for standard IEEE systems. The paper describes the state estimation technique that implements weighted least square (WLS) estimation and compares the error associated with measurements and their estimated values for various standard IEEE test bus systems.