A precision decimal inch tape measure has a housing that holds a retractable measurement tape. The retractable measurement tape has a hook on an end. The retractable measurement tape has an upper measurement scale defined along an upper portion of the retractable measurement tape and a lower measurement scale defined along a lower portion of the retractable measurement tape. Both the upper measurement scale and the lower measurement scale indicate inches divided into decimal divisions. The upper measurement scale includes a cumulative foot indicia and the lower measurement scale includes a cumulative inch indicia. The cumulative foot indicia is indicated in red and the cumulative inch indicia is indicated in black. The precision decimal inch tape measure is designed to work with drawings produced in decimal inches as is the preferred standard of CAD drawings. This instant invention works with cumulative feet and inches or with cumulative inches.