Right Size Parking Calculator

The King County Right Size Parking Calculator provides estimated parking/unit ratios for multi-family developments throughout urban areas of Seattle’s county.

The Right Size Parking Calculator estimates parking usage based on a powerful model we developed using actual parking use data collected by King County for more than 200 developments in urban and suburban localities. These parking use data were correlated with factors related to the building, its occupants, and its surroundings—particularly transit, parking pricing, and population and job concentrations—to build the model.

The resulting parking utilization model and web tool provide support to challenge the over reliance on parking guidelines that promote a one-size-fits-all approach for suburbs and urban areas with transit. 

The calculator can help analysts, planners, developers, and community members weigh factors that will affect parking use at multi-family housing sites. It will help them consider how much parking is “just enough” when making economic, regulatory, and community decisions about development.