This report describes the rationale for a series of common and broadly accepted soil health indicators to support policy. The focus is on soil threats, and indicators were selected in view of their appropriateness for assessing the condition of soil, its degradation, its resilience and its valuable services. For each indicator, a rationale is provided for using thresholds as critical limits to indicate that soil is in good condition, i.e. healthy soil, in respect of of specific soil functions and local conditions.