Purpose: This study examines the relationship of socio-economic characteristics of start-ups with their size in Gujarat, India. It also assesses the determinants affecting the annual sale of start-ups.
 Methods: It includes primary information based on a survey of 120 founders of start-ups. Linear and semi-log linear regression models have been applied to assess the determinants of start-ups. Probit regression models have been considered to assess the factors affecting the annual sale of the start-ups.
 Results: Stage of start-up, the participation of founders in conferences, educational qualification, and new products launched by start-ups, professional connections of founders, source of funding, and support from incubator/accelerator/supporting organizations are found crucial determinants of start-up size in Gujarat. The annual sales of the start-ups are positively associated with stage of start-up, support from a mentor, team members, founder's academic qualification, and collaboration with national or international organizations, unskilled workers.
 Implications: Technology transfer and commercialization, development of new products, government regulations, the requirement of costumers, free rights for entrepreneurs, appropriate financial support for new entrepreneurs, transparency and clarity in government policies, the establishment of high-tech start-ups, and development of digital infrastructure, increase in R&D spending in research academia, and association of research institutions with entrepreneurs would be conducive to create an appropriate start-ups ecosystem and to reduce regional development disparities across Indian states. Subsequently, it would be helpful to increase sustainable development in India. 
 Originality: This study has used primary information of 120 founders of start-ups to assess the determinants, and the factors affecting annual sales of start-ups using the regression model in, Gujrat, India. Thus, it has an empirical contribution to the body of knowledge.
 Limitations: This study could not provide rational justifications on most factors that show an insignificant impact on start-ups due to the small sample size. Further research, therefore, may be considered to identify the association of start-up size with the variables using a large sample size in India.