The Clemson Watermark Calculator is a tool that can be used to assist with determining the weighted average of multiple Watermark 200SS sensors at given depths to determine irrigation thresholds. The Watermark 200SS soil moisture sensor irrigation weighted average thresholds calculated here are based on the value obtained at each sensor at specific depths as a function of the total soil profile depth measured. This calculator does not account for faulty equipment or inaccurate inputs. All calculations were derived from Irrometer Company Inc. recommendations. For comparison of these results to the Irrometer irrigation threshold recommendations, click here.

The calculated irrigation threshold is calculated from the selected soil texture and allowable water depletion. As an alternative, a manually entered irrigation threshold can be input below.