Karachi is the largest and most populous city in Pakistan. The population of Karachi is estimated to be around 20.3 million as per Census 2023. The population and demographic distribution in the megacity has undergone numerous changes over the past 150 years. On 14th August, 1947, when it became the capital city of Pakistan, its population was about 450,000 inhabitants However, the population rapidly grew with large influx of Muslim refugees after independence in 1947. By 1951, the city population had crossed one million mark. In the following decade, the rate of growth of Karachi was over 80 percent. Today, the city has grown 40 times its size in 1947 when it became the country's first capital. Although, Islamabad remains the nation's capital since the 1960s, the city's population continues to grow at about 5% per annum, largely thanks to its strong economic base. The population growth of various districts of Karachi over the years is as follows: