omote-daka was calculated based on the land survey officially recognized by the edo bakufu; however , in many domains the actual uchi-daka was higher than omote-daka and also increasing , thanks to the progress of development of new field in 17th century , the land survey within domains that was based on the increased productivity by innovation of agricultural technique (farming equipments , fertilizer ), and tax reform by monopolization of indigenous products . 表高は江戸幕府公認の検地によって算定された石高だが、実際の藩内では17世紀に進んだ新田開発や、農業技術（農機具・肥料等）の革新による生産力の増大に基づいた藩内検地、専売制による特産品の税高改定などによって、多くの藩では内高は表高を上回って増大していた。
