The ZIP code 90401 in Santa Monica, California, has experienced steady population growth over the past decade, with the population increasing from 6,319 in 2010 to 7,259 in 2022. The population density has also risen, reaching 8,343.68 people per square mile in 2022, up from 7,263.22 in 2010. Given the ZIP code's size of 0.87 square miles, the estimated number of housing units corresponding to the 2022 population is approximately 2,781, based on the national average household size of 2.61.

The population density of 90401 falls within the urban classification range, which is characterized by densities between 3,000 and 10,000 people per square mile. Urban areas typically feature a mix of multi-story residential buildings, commercial buildings, and high levels of infrastructure and services. The lifestyle in such areas is fast-paced, diverse, and culturally rich, suitable for individuals and families who enjoy vibrant city life with extensive public transport, restaurants, theaters, and museums.

The consistent population growth and increasing density in ZIP code 90401 suggest ongoing urban development activity to accommodate the growing population. This may involve the construction of new multi-story residential buildings, the expansion of commercial districts, and the enhancement of infrastructure and services to meet the needs of the growing community.