The relationship between farm size and productivity has been a topic of interest in agricultural research for decades due to the significance of agriculture in rural economies and its potential to reduce poverty and promote inclusive growth. The relationship between farm size and productivity is influenced by factors such as the type of crop being produced, costs of cultivation, farm management practices, access to inputs and markets and socio-economic conditions. This paper aims to investigate the relationship between farm size and productivity in the context of farming households, their cost of cultivation and the types of crops they produce. Using the Cobb–Douglas production function, the present study estimates the regression function for principal crops such as cotton and paddy in the study area. The findings reveal strong evidence of an inverse relationship between farm size and productivity, indicating that small and marginal farmers are more productive in wetland cultivation (paddy). In contrast, medium and large farmers are more productive in dry land cultivation (cotton). The paper also investigates the availability and accessibility of credit facilities for different farm sizes. It concludes that small and marginal farmers depend mainly on non-institutional credit agencies compared to medium and large farmers.