This paper present a compute based method of determining of off-design peek performance characteristics of horizontal axis wind turbine, new method based on analytical approach and an experimental verification based on reading taken from wind farm at Jamgodrani Dewas in Madhya Pradesh located at 76°10'E longitude and 22°59' N latitudes at the height of 560 m above mean sea level. The theoretical method of performance prediction is based different strip theory, in which a blade is divided into 100 radial elements. The blade chord, its twist and its elementary power co-efficient at each station were determined. The iterative process required for the convergence of speed interference factor and for maximization of power coefficient. The design process begins right at maximum power point, rather than searching of point of maximum power and then doing the computations. Analytical approach and an experimental verification of 225kW turbine come out 620.82 kWh and 487.56 kWh power generated respectively.