The knowledge of vehicle mass is very important for the proper functioning of various vehicle stability control systems and vehicle state observers. A method for estimating the vehicle mass in real time is presented. Traditional mass estimation methods suffer due the lack of the knowledge of vehicle parameters, road surface conditions and most importantly the effect of the vehicle transmission. To resolve these issues, a vehicle model independent method is utilized in conjunction with a drivetrain torque output observer to obtain the estimate of the vehicle mass. Simulations and experimental track tests indicate that the method is able to accurately estimate the vehicle mass with a relatively fast rate of convergence compared to traditional methods.