The PARATILL SUBSOILER is designed to till soil to a depth of up to 18 inches, which can help break up compacted soil and improve drainage. The actual tilling depth will depend on the specific model of the subsoiler used, as well as the soil type and conditions. However, with the ability to till soil to a depth of up to 18 inches, the PARATILL SUBSOILER can be an effective tool for improving soil health and increasing crop yield.