Population
When comparing the various other states to California, the largest state in the US by population, you can see how skewed the Senate is as well as just how large California is.
Data taken from the 2019 Census Bureau estimates and 2020 CIA World Factbook estimates
After the 2020 Census, some states gained congressional districts, while others lost them. This map shows how the state's ratio of population to the amount of representative is compared to the average of 766,771 people per representative.