Abstract: A measurement arithmetic based on virtual equivalent sensor and linear interpolation was presented, which was applied to aircraft fuel quantity gaging. The aircraft fuel surface which was defined by more than three fuel sensor′s measurement value could be also expressed with one virtual equivalent sensor located in special situation in the fuel tank. In this equivalent principle, fuel quantity could be acquired having three-dimensional linear interpolation through the three-dimensional data stable showing the relation between fuel quantity and the virtual equivalent sensor, aircraft attitude information. Effectiveness and precise of the proposed method were demonstrated by simulation results adopting Solidworks software. The results show that the measurement arithmetic is stable, reliable and effective. Because of the application of the equivalent sensor, data quantity in three-dimensional table is greatly compressed, which makes the interpolation method easy to be realized in actual aircraft fuel quantity gaging system.