The soil texture triangle is a diagram used to classify soils based on their texture, which is determined by the proportions of sand, silt, and clay particles in the soil. The triangle has three sides, each representing one of the three soil particle sizes. The corners of the triangle represent 100% of one particle size and 0% of the other two. The sides of the triangle represent all possible combinations of the three particle sizes.

To determine the soil texture, the percentage of sand, silt, and clay in a soil sample is determined and then plotted on the soil texture triangle. The point where the three values intersect will fall within one of the soil texture classes. There are 12 soil texture classes, ranging from sand to clay loam, sandy loam, loam, silt loam, sandy clay loam, clay loam, sandy clay, silty clay loam, sandy clay, silty clay, and clay.