In this paper speed estimation methods for low cost, variable frequency induction motor drives are investigated. Such methods are required to minimize the computational effort and show little parameter dependence. Existing methods have limitations regarding the speed range or are applicable only if the motor size is such that certain requirements are met. Two methods described in the literature are considered. Three new methods of speed estimation are developed to improve their performance. The model used for each estimation method is described. Their computational requirements are evaluated. To asses the speed estimation methods, load tests are performed on 3 different motors rated at 1.1kW, 2.2 kW and 4 kW. The tests are performed by driving the motors between 10 to 70Hz, at 10 Hz steps. Each estimation method is modeled using MATLAB. Voltage and current data obtained during the tests are used to predict the motor speed at different load levels. Investigation of the findings indicates that one proposed approach promises good performance for a wide frequency range and for all the motor sizes. However, it is found that very low frequency (about 10 Hz or less) predictions need further attention.