Sandwip is an island along the south eastern coast of Bangladesh. Sandwip is a sub-division of Chittagong district located at 22.490513°N 91.421185°E. It is situated at the estuary of the Meghna River on the Bay of Bengal and separated from the Chittagong coast by the Sandwip channel. It has a population of nearly 400,000. There are 15 unions in Sandwip. There are also as many as fifteen different wards, 62 mahallas and 34 villages on the Sandwip Island. The entire island is 50 kilometres long and 5-15 kilometres wide with an area of 762.42 km2. Sandwip has a very large potential for tidal power generation with a tidal variation of 5-6 m. A flood control barrage exists around the entire island and this contains 28 sluice gates. Considering each sluice gate is capable for one turbine and one generator, a very large amount of power can be generated from Sandwip. The main objective of this paper is to utilize these sluice gates to find the potentiality of tidal power in Sandwip by using one turbine for both one way & two way power generation technology & support the results by proper mathematical model. The mathematical regime proposed in this paper is very simple and effective and only associated with two variables, surface area of the basin and tidal variations. Based on this methodology the outputs are 0.028AR2 and 0.056AR2 for one way and two way power generation systems respectively. Because of the massive size of the oceans and the prediction accuracy of tidal, it is more preferable than any other renewable sources. While the discussion in this paper focuses mainly on Sandwip, the messages are relevant for other areas that has the potential to engage in Tidal Power.