A method for laterally extrapolating shallow soil properties using soil samples and seismic amplitude data within a seismic coverage area entails obtaining seismic amplitude data for the seismic coverage area and obtaining average soil property and soil impedance data for locations in the seismic coverage area. The seismic amplitude data is compared with the soil impedance data at locations in the seismic coverage area forming an amplitude impendence formula. The seismic amplitude data is converted to soil-calibrated impedance data using the amplitude impendence formula. The method continues by comparing an average of desired soil property and the soil impedance data at locations in the seismic coverage area forming a soil property-impendence formula. A target soil property is selected and the soil calibrated impedance data is converted to the target soil property using the soil property impendence formula. The method ends by extrapolating the target soil property over the entire seismic coverage area.